Have you found reliable online used vinyl vendors?

Try either of these online merchants. I've had good luck with both of them.

http://www.discogs.com/
http://www.musicstack.com/

Mike, (wwjdmike) here on AudiogoN has some excellent used LPs at GREAT prices. I've ordered many times from him and have always been very pleased.

He doesn't have a list per se, so you have to just scroll through all of his listings here, but well worth the time and effort.

Highly recommended!!!

If you're careful, you can get some good records on ebay. Quality sellers understand the importance of good feedback, and do whatever they can to keep it as high as possible.

If you know what you are doing on Amazon, you can do extremely well there buying used. There's 2 main things to consider when shopping with them. The first is that most of the used LP's are not sold directly by Amazon, but by their marketplace sellers. Going that route sounds risky, but its not. Not many people know this, but Amazon has what they call an A-Z guarantee. If the item is not what the seller states or you don't get it for any reason, you file an A-Z claim. Amazon makes sure you get a refund. I've had to use it several times myself. They don't play games. You get your money back.