No one seems to want to give you an answer and that may be because it is very hard without knowing the actual chips involved. If you are getting a collection that includes duplicates or a lot of other chips you don't want in your collection, then obviously you should offer less. When working any deal keep in mind that the first person who speaks, loses. In other words find out how much the seller wants and then decide if it is fair. What others have said here is true though - don't expect to sell the chips at even low TCR value. I had a deal to sell my roulette wheel (worth $1500 cash or so) for $1800 in high value obsolete chips. I turned it down because I didn't think I would get the value for the chips I needed to make the whole thing work.