I've found that patience is the key. And timing- I've bought a few things from guys on here that were real bargains just because I happened to be on the site when the item was first posted. I recently bought a 71 Swinger as a donor car for my 71 Demon build. I could not find a front bench seat with the headrests and good tracks for under $350 plus shipping if they were willing to ship. Also needed the front windshield, both front fenders, and the dash. Got the Swinger for $800 delivered and don't have to pay for all the different parts or shipping. Deals are out there but the market conditions set the price- supply and demand. If the price is too high the part won't sell. If it does sell then obviously the price wasn't too high.
What gets me is the low ballers. They are just offensive to me.