thinking of buying a used (like new) 1998-1999 scag "gear drive" 36" walk behind. it has a kawasaki engine (13 hp?). don't know anything about these mowers...or walk behinds, for that matter. it has very low hours and has been strictly used by a homeowner for his 2 acres. it's suppose to be "like new". what's it worth....how much should i pay??? what's with the gear drives...vs. new belt drive? would this be a good mower for me to use if i am mowing about 20-30 residential sized lawns (1 acre or less)??? i'm only doing this work (and maybe lawn edging) to earn some money to help pay my college tuition.