When the thied engine on my old tractor finally gave up the ghost, i decided it was time for a better newer engine, so i did that. So, if you can afford a new tractor, go buy one. But, if the only problem is a wheel and bearings, i'd fix it! And, buy hubby a hand-operated grease gun and several tubes of grease, and tell him to get busy greasing all of the fittings! An hour of laying under the machine is far too long, to find all of the grease fittings! And, a tube of grease, and even a grease gun, is far cheaper than a hundred bucks for new parts!

I'd fix it if I were you!!