I've bought several times on GB, but using 'buy now' rather than actual auctions--and have had good experiences all around, with 4-5 vendors. I've bid in actual auctions on items everyone knew were going to blast into the stratosphere, but never wanted one of those bad enough to win at the end. I do like buying at LGS (esp. at the range where we're members) but then I pay for the (excellent) service and convenience. Usually, by the time I get around to buying something, I usually know exactly what I'm looking for, and can find it on GB (or other online sites) for substantially less than LGS's; and there are local FFL's that give terrific service on the transfers. Just make sure you account for the transfer, the shipping, and the typical ~3% credit card fee, when figuring the GB price.