There are lots of variables- available money, intended use, typical weather/conditions, future expanded needs, resale value, operator ability, etc. With our uses on a horse farm, cutting fire wood, snow, soft fields, etc., no way would a 2WD get the job done. We would either tear up the land, or simply not be able to do the work. You can finagle a 2WD and get many things done, but not everything. With a round bale on the loader, you couldn't get a 2WD out to our round feeder, unless the ground is frozen.
I know this from experience-we used to have a Ford 3600 2WD. We got it stuck many times doing the same work that we use the 4WD now, with no issues.
Plus, the mowing that I do with my Kubota depends heavily on 4WD- some of it can't be done otherwise, no matter what you try in 2WD.
If you budget is tight, make what you have work. But, it is worth at least looking at replacing the tractor with a used 4WD with a loader- it might make more financial sense in the long run.