It's a lot of money. But so is a horse farm split over two properties with a large arena. I don't assume what other people can and can't afford, but that sounds to me like a reasonably expensive operation. And if you're planning to plow and seed then you need a decent machine.
One big question here is implements - do you already have them or do you need them? You'll need that plow and a seed drill. In my part of the world we avoid plowing as much as possible, if we can we spray the field then direct drill through the stubble. Avoids loss of soil to wind, and doesn't break the soil structure so much. Often plowing and seeding would be a job you'd contract out - the cost of implements is often more than you're saving on a smallish farm - especially implements suited to an M5. And planting can be quite technical, someone who knows what they're doing will pay for themselves.
What will you be planting? Oats? I'm not clear on what horses would need.....but I'm guessing it's a regular crop or hay, not just grazing grass?
I'm interested in your bush hog that you can tow behind an ATV. Usually that'd be a self powered mower (i.e. has gas motors on each spindle)? Sounds unusual that you'd use an implement like that behind an M5.
I don't want to be impolite, but it sounds to me like you have an idea of the jobs you want to do, but not all the info about the mechanics of doing those jobs. That's not a problem, hell, a lot of guys getting into tractors also have no idea when they start (I certainly had no idea). Dealers should be used to that. They shouldn't be treating you differently as a woman who's learning than a guy who's learning. But you do also have to be willing to learn - a few of the things you're saying don't quite line up (may be how you're writing it, may be how you're thinking about it). So a dealer may be trying to say "it's not quite like that" and you may be interpreting that as "you're a woman you don't know what you're doing."
In that situation I'd be tempted to take it on head on. I'd say to the dealer "it's my operation and my tractor. My husband doesn't wish to be involved. Here's what I want to do, I need your advice on how best to get it done, and what I need to buy to do it. I'm potentially going to need a tractor and a bunch of implements, but I need to know what exactly."
I'd guess that he's going to give you advice that some of the jobs you want to do really aren't economic to do yourself - they're technical (so if you get them wrong your crop yield will be poor), and they need big expensive implements for something that you're doing once a year on a few acres. Hiring that out will often be way more economic. And if you contract those jobs out instead of doing them yourself, what you have left might not need an M5, it might be Grand L territory. Certainly a Grand L would bush hog, move manure, drag the arena, and drill post holes. Moving 1000lb bales is a trick though - that takes a lot of machine - I think in theory a Grand L will do it, but an MX or M would give a lot more safety margin.
Again, not trying to be rude or doing the suck eggs thing, but my process here would be:
1. Double check your tasks. Which will you definitely do v's contract out. The plowing and seeding is the one in question for me - how often will you do it, what do the implements cost? That could be $20-30K of implements to do that (or maybe you'd rent them every year?), probably a contractor could do that for $1K a year and do a better job of it
2. Then size tractor to your biggest job. I think that'd be moving bales if you're not plowing/seeding. And actually, a smaller M would probably plow/seed fine. If the bale moving is the biggest task, then check the brochures to see what a Grand L (the 60 series, not the 02 series) will lift. You want about 50% margin for safety really. I suspect a Grand L is a bit small, an MX or a smaller M could do it just fine
3. Then ask yourself "can I afford more and do I want more". My 5c would be that an M5 is a hell of a lot of tractor on 55 acres, but if you want one and can afford it, then buy it. You'll love it. But it'd be a heavy machine for dragging the arena - it might chew it up when you're dragging it. What do other people drag their arenas with? And I guess you'll want to use the FEL to get manure out of the barn/horse stalls? Does that limit your maximum size at all? If you can avoid having to shovel it by hand too much that'd be a big benefit I guess. Dad had an older mid tier M on 80 acres, and it was plenty of machine for lots of things.
4. Then plan out your options and implements.
- I'd guess you'd want a cab - but if you have to go into a barn be careful on height (a ROPS machine you can fold the ROPS down, but obviously a cab keeps heat and bugs and rain off you).
- You want a FEL
- That means you need some sort of ballast. I personally wouldn't load the tires, because I think that'd be extra weight in the arena. A ballast box you can put on when you need it, take it off when you want a lighter machine. But others will have a different opinion - loaded tires are very popular because with a ballast box there's always a tendency to not bother putting it on (it's a hassle). And lifting bales without ballast is dangerous - a tractor with the back wheels off the ground tips over very easily - the rear wheels gives you all the stability
- If you have 3 pt hitch implements on a machine that big, they're too heavy to horse around to attach them. So you want a quick hitch, and that means the bush hog and ballast box and plow and seeder all need to be quick hitch compatible
- I suspect you'd want a much bigger bush hog than you have - that was Dad's reason for a large machine - to swing a big bush hog and limit how much time he spent mowing the fields. His was a dual spindle bush hog, which lets you cut a much wider swath without hanging out too far (a single spindle bush hog sticks out a long way - they have to be square - a dual spindle bush hog will be a rectangle)
- You want a post hole auger. Those things can be death traps - so make sure you know what you're doing. Around us people bang in posts rather than drill them nowadays - there's a post rammer for the back of the tractor. And if you're drilling, a lot of people would rent an excavator with a drill - if you're only putting in a couple fences then rent the right machine and do it once. (Mum is putting a fence in at the moment, she's hiring it out. Dad in the last few years of his life did the same - gives employment to local people, and again doesn't buy an expensive implement that you only use occasionally. And I personally dislike building fences, it's hard work that is better done by an expert. Specially horse fences I suspect - built wrong you could hurt a horse. Funny story, when Dad passed an experienced guy leased the farm, and bought quite a few of Dad's implements - he had good stuff. But he took one look at the 3ph posthole auger and said "nope, those things hurt people, I'm not taking that." He's the guy who's building Mum's fence, he knows what he's doing).
- Forks for the bales? Around us people buy "soft hands" which are a grapple thing for round bales. Doesn't puncture the plastic wrap
- Do you have sticks and trash to move / trees to clean up around? Grapples are excellent for that
- Plow. Seeder
- What do you drag the arena with?
- Do you need some sort of manure wagon/spreader? Do you spread it in liquid, or is it mostly dry?
Also, feel free to map out a bit more what you're trying to do. Plenty of experience on here, people will be happy to give you their thoughts, much as I've done. Doesn't mean they're all right in their opinions, but listening to people's opinions lets you pick and choose.
I did like the suggestion above about two tractors. Mum and Dad always had two tractors - one with the loader, one towing the trailer. If you're spreading manure, I can imagine a big machine with a PTO- or hydraulic- driven manure wagon. And a small machine with a small FEL that will go into the barn/stalls, haul the manure out. That'd definitely beat hand shovelling. Depending on size of your barn, that second machine could be a skid steer......if that isn't going to chew up your floor too much.
I know I've assumed a lot here, but trying to be helpful.