One of the most useful tools Ebay offers is the "check completed auctions" option in searches. On common items (defined as items that seem to always be available on ebay) this is a great way to if you want to see the range an item typically goes for. Typically, you bid the lowest amount that an item has sold for previously, you will eventually win one at that price – even if the average selling price is higher! Granted, it takes some patience. For example, I recently needed to purchase two Ohaus Triple-Beam balances for a summer science camp program. These generally sell for $35-$45 on ebay and there are usually a half dozen or so up for auction at any given time. It took several months, and I lost about 30-40 auctions on them, but I eventually got two for $25 or less by being patient.

Casino chips can be different, as you can’t always find that one particular chip available. But ultimately, there is no substitute for a little research and some note taking. As I have said before, I would argue that knowledge is the backbone of any hobby. It isn’t the stuff so much as the stories behind the stuff that makes it fun to collect. As such, I would think that doing research on sales prices would be right up any collector’s alley.