WA state sales tax tokens are fairly common among tax tokens. You'll come across them frequently in random token lots and junk bins at coin show and such. Many come up on
ebay in the exonumia section. They usually sell for a couple bucks a piece in unc, if sold individually, but it take's forever to sell a 1/2 jar full that way. IMHO not worth the time and effort. Problem is there is a very small collectors market for them. Not many people alive today ever heard of them, and even less of those who want to buy or collect them. Best bet is to list them as a lot, with good photos and description. Just make sure your starting bid or buy it now price is high enough to cover your costs and shipping.