My and my friends always liked brewing our own decks so to encourage that and discourage net decking we've come up with our own casual budget format we call Bargain. The only special rules are your maindeck must be $30 or less on mtg goldfish and your leftover money plus an additional $5 can go toward a sideboard. We just check every couple of months whether a deck has gone way over budget and we haven't had the need to ban or restrict any cards yet.