Speaking as a Marketer, the list has value for sure, but the value would be dependent on metrics associated with the list - depending on the channel (I gather its multiple channels? A bit of a mix?) the engagement of the list would be important. If you've never used it and its 'untested' it has less value.
TBH you can already target interest on lots of advertising platforms, including crypto so your pricing would need to be aware of that, and you'd need to know how responsive this group is. As you know the crypto crowd tends to enjoy its privacy so anyone buying or renting this list might find themselves with a new group of enemies rather than a group of customers, especially if these people havent opted in. (by the way a double opt in group would catch a premium.)
I do this stuff for a living, my knee jerk assumption is your list isn't worth as much as you think it is, but I don't know the specifics.
To be transparent, I run EngineBloc - a crypto focused marketing agency.
Thanks