They don’t come up very frequently, to my knowledge. I was contacted once about interest in my sample set from a member in Canada, though it might have pre-dated this site. Holdem Poker Chips was the original vendor as far as I know.
I have not been actively buying and selling lately, so take my estimate with a grain of salt, but a good breakdown and/or motivated buyer should fetch you a buck or two per chip.
It’s a great set, in my opinion, but the lack of QC - namely on misshapen inlays - turns some people off. The large recess in the center makes them easy to relabel as well.