hey. im just coming off my 05 crf250x and im getting a used yz450f. there is a 2009 yz450 with roughly 30 hours on it, needs a new back tire on it. asking $4300 i have a feeling it wasnt maintained that well and i want to make sure my next bike doesnt give me any problems this summer. there is a 2008 yz450 with a full fmf carbon fiber exhaust, has about 25 hours on it, pro taper bars, excel rims, and hour meter. in very good shape with good tires and sprockets. asking $4300 last but not least, another 2008 yz450. the guy rebuilt it after 50 hours of driving, stainless steel valves.., dna racing wheels, blue hubs, s.s oil filter, taper bars, unbreakable levers, monster graphics. all work done by a yamaha mechanic. this thing is decked out for $4400. I just want to hear what you guys have to say about these bikes. they are are in awesome shape and look great. Im leaning towards the 2008 with S.S valves but dad disagrees because it was rebuilt. that means there are less chances of something seizing up on it right? i always maintain my bikes well and just do trail driving. _Thanks and id love to hear what you have to say.