I've seen a few of these and have a friend who has participated. The lure of a tasting for me is to try wines that are too pricey to buy without knowing if I'll like them, and to split that (discounted) price of several different bottles with maybe a dozen other people since they are small pours. If I find one I really enjoy, I don't feel bad paying a lot of money for it. Before the complete and total lock-down of Illinois, we used to do these at a couple different wine shops, maybe once a month, especially if they had a representative from the winery leading it. I think the last one we did was a Gundlach Bundschu tasting, which is a winery we always enjoy.

If I have to buy the whole bottle(s) to do the tasting, it defeats the purpose.