Used is used, no warranty expressed or implied. How it works I did that as well with my second M9 and was prepared from the outset to put some bucks in it, which I have btw. I just spent 2100 at my dealer for various issues to get addressed but thank the Lord none were catastropic engine related issues.
I had leaking seals in the engine (replaced), overhead adjustment, valves noisy (adjusted), multi function switch inoperable (replaced), let hand outboard planetary bushings sloppy (replaced all the bushings and bearings and seals), thermostat and rad cap (replaced and renewed), secondary fuel filter sucking air (replaced and filter element and water ring replaced as well). had the tractor put on the dyno and load tested, it's making 89 horses at the PTO. Good to go. Forgot, had the injectors pulled and pattern and pop off pressure tested as well. All good.
$964.14 in parts and $1200.00 in labor and that don't include what I did in my shop. I replaced the right outboard planetary inner seal, replaced both tie rod ends, put new shoes and tubes all around (that was 4 grand in rubber and tubes alone), changed all the fluids and filters including the outer and inner air filters, completely stripped the tractor down to the chassis only, repainted ALL the tin and had the upper bonnet repaired and repainted (200 bucks) at the body shop, replaced the crappy Kubota vinyl seat and suspension with a Grammer clone and a new K&M suspension (300 bucks), Power washed the chassis and engine with Zep, 3 times (was filthy, I hate filthy tractors), repainted the entire running gear and adjusted the travelling clutch and pto clutch lockup pressure (I have the WSM and the required gauges and adapters here), replaced the incandescent headlight bulbs with LED bulbs, sanded and repainted all the rims and cast centers, put everything back together.
It's finished and I fully expected to do all that and the motor if necessary but it wasn't.
You can never buy used and not expect issues, the way it plays. People don't trade or off any unit because it's perfect, they sell it because it's either not big enough or is has issues and they feel it's not worthwhile to repair and that likelyhood increases the older it is.
I did a bunch of the work myself but I still paid out a substantial sum. I bought it for $18K with a loader, SSQA and 2 buckets, one a material bucket and the other a HD dirt bucket. Nice thing is, because I already have an M that I bought new in 2004, everything interchanges and I only need to stock one set of filters and they both take the same fluids and oils.
Is it worth it? Damn right it is. I have no regrets and I own two pristine M's as well that are both pre 2 engines with no emissions crap to contend with down the road.
My biased opinion is, the M9's are the best utility AG tractors Kubota ever built with the hydraulic shuttle and and pto clutch packs. As they age they will require parts, just how it plays.
Almost forgot, I added a Tuff Top canopy as well. Don't kike the sun on my almost bald head.....
In summary, I paid 18 and put in about another 6 or so which brings me up to about 24. A new M9 hydraulic shuttle with loader listed for 45K. I know because I have the original paperwork for mine I bought new.
I'll sell you the one I restored for 30 if you want to buy it. It's most likely appreciating in value anyway as all the no emissions units are.
I wouldn't whine about what a motor will cost you, I look at them as an investment with a good final return when you decide to sell it.
My 2 cents for what it's worth.