I agree about the shipping cost. Haven't bought bike stuff, but many times I've refused to bid on something because the seller jacks up the s/h way beyond what it would actually cost--easily verified by looking at similar items and their prices.
Otherwise, no real probs buying stuff and I've even ventured into selling. Right now am trying to decide what to do w/'82 Schwinn Superior--basically a "baby Paramount" w/90% campy gear, etc. But that discussion is going on over in the classic/vintage forum!