These are good thoughts guys. Forget the Scott, I'll stick with my current bike for now. Is it generally a good idea to buy used drivetrain parts? I mean, the cassette, chain, and front rings and shifters are all parts that wear out plus they tend to wear together... I've never been to Veloswap but I will check it out. Are there generally pretty good deals there? I just don't have a great feel for valuing used bicycle parts (especially wheels) so maybe it'd be a good idea to go with someone with an eye for the stuff.
Cassette and chain are usually best to buy new unless you can find somebody who's selling after only a little use. You can still get them cheap though, Tiagra/105 level is usually alright. Cassettes should not need replacing as often as the chain unless you wait forever, then you should do both at the same time. Hardly anyone wears out front rings, and then as long as they're not ramped and pinned you can just flip 'em around and have a whole new side (this is one of the things I like about 1x8/9/10's). Used is no problem there usually. Shifty things don't really wear out until they break. I mean I guess you could wear out derailleur pulleys over time, but they don't need to transfer any power so it doesn't matter if they're worn out or not, until your chain literally falls off. Just know what to look for basically. If you're looking at a chain, check wear with a ruler or fresh chain. If you're looking at gears, check the teeth for the "shark fin" look. Derailleurs and shifters, make sure everything moves smoothly and there's little slop.
Wheels should be true and evenly tensioned, the bearings should turn with no roughness or slop when clamped in a frame, and the rims shouldn't be worn too much from brake wear. Look for cracks near spoke holes in the hub and rim, and near the rim seam. Ask about the build history, e.g. has there ever been a broken spoke, what was done about it, etc. Breaking a spoke without rebuilding the wheel isn't a dealbreaker, but it is strike one if you don't know the situation surrounding the break.
Maybe you guys could have a MMM meetup at this thing? that would be cool and helpful. Although if you can't get anybody to go with you, keep an eye on Craigslist and eBay completed listings to get an idea of what used parts go for. Then factor in that they will go cheaper in person. There's your price. Beyond that, don't worry too much if you maybe overpay a little. A deal is a deal, even if it's not the absolute best deal you could have made.
Don't be afraid to walk away without whatever you wanted to buy. Don't buy a bunch of shit you don't need. Don't be afraid to ask questions, even of other dudes just walking around if you want a quick opinion.
