Swiss-army type machines have their place. They can do alot of different things. But certainly arent the best at any of them.
If you only have room in your pocket for a swiss army knife, its fine. It can open cans, but not as good as a can opener. It can turn a screw, but not as good as a screwdriver. IT can pop a cork, but not as good as a corkscrew. You get the idea...
A ZTR, while a single purpose machine, it the best for mowing you acreage. And even if purchased new, maybe 8-9k for a good one that will last.
A tractor, with a loader and possibly a rear blade for doing your drive, something in the B-sized kubota, would run you maybe 16k new,
That puts you at your 25k budget. But, nothing at all wrong with used. A good commercial grade, low hour ZTR can be had for 4-5k, and a similar sized tractor used and lower hours, maybe 10k. So you could save 10k just by buying used if you so choose. But in the end, I think you will be far happier than with a swiss-army machine.
When I bought my place, I bought the kubota as a swiss army machine, cause it was all my budget would allow. I used a old lawnmower in close and a 3PH mower for everything else. I now own a ZTR. No comparison. If it is in your budget, get it now.