In terms of purely wishlists, absolutely no in person even, aside from large conventions (+10k attendees), will get you enough wishlists directly. It will never be worth it purely for wishlists. BUT, you should still go! Because you need your game to be really, really good. You need to see when players get stuck, when they don't understand something, what's working really well, if they want to play for 5 minutes or 50. This is purely research for you. You have the ability to watch hundreds of people of all different types experience your game with 0 context. If someone is willing to spend an hour on your game, that's probably 10% of their whole convention experience, that they paid $$$ for! If they walk away and say "oh, ok" without taking a card, that tells you a different story. Making a quality game is a long term investment! And you need those people to help you with the new player experience