Buy a good reputable name... the AB RIBs 10-20 years ago were bulletproof. I bought a used 10 footer, it had two small round patches. It never leaked a bit the whole time I had it, I didnt pamper it and just ran heck out of it. Still going strong when I sold that boat. It sounds like the Avon's are pretty good too. There is one more brand from that time period that was very good , but it evades me. Do not buy a West Marine
unless the Zodiac
is the commercial
type. Achilles are good boats but you dont seem to see man RIBS.
My AB 10 ft with double floor was quite heavy. I had a mid 90's Yamaha 15 hp two stroke that made it fly.
It would be easy to get a problem in an outboard... so not sure what to telly ou. I look for one that has come out of some old guys garage which he bought for lake fishing
and didnt use much. Sometimes a 15 year old engine
will look like brand new. The 90's Yamahas are great engines. The old Evinrude
10-15 hp are realatively easy to repair and to get parts
for. You definitely want to see the engine
run. Look for water spitting out the back. Very often a great old engine that has sat will not spit the water out but run fine. It's a good way to negotiate... every time this has happend to me it was simply a matter of clearing the little tube the cooling
water comes out of! The trouble is, you cant tell if the engine has bad main bearings or a spun prop hub bytesting it in a can. So if the engine is visibly "very used" I would pass due to that possibility. If it is clean as a pin and garaged, but water doesnt spit out... buy it!