If that tractor is in good shape, you don't wanna pass it up- especially for that price. I had one (same year too) several years ago, that I purchased used from a Mahindra tractor dealer, and wish I never would have sold it. It is Definately a workhorse! I think it had 879 hours on it and I gave $6,700 for it. I kept it 2 or 3 years, put about 300 hours on it, and sold it for $6,600! And was still in as good of shape as when I bought it. Man that thing was a beast!
Within them 300 hours I put on it, I had a couple minor electrical problems, the power steering cylinder down under the front axle had to be re-packed once, the PTO shaft seal had to be replaced once, and the engine Oil Pan had to be replaced once (due to me getting hung up on a lighter stump in a clear-cut). And I think I replaced the headlight bulbs once also. All these situations were fairly easy fixes...
Just to let you know, the CarQuest engine oil filter number for the 97' Mahindra 485 DI is #85775.
I hope this helps ya,
Travis R