Do you want to support Capcom as a business, or do you want them to disregard potential revenue in order to deliver the best game possible.
Remember that one ensures Capcom is more likely to keep making fighting games and receiving extra investment for development, the other runs the risk of the entire fighting game division going belly-up with one full-retail release not doing so well.
If you’re a poster here, it’s very likely you’ll get $60 worth of playtime out of the content you have access to. However, if the base game is not worth the money, then by all means don’t purchase it. No one wants you to waste your money.