Well you save 20% on all new games, get reward certificates for points earned (dollars spent) and also pre-orders, saving on pre-owned, getting more on trade-ins etc etc. I can't find the current price but if you can still get GCU for $30 bucks then the answer is absolutely.
It pays for itself rather quickly. And the extra perks besides getting $60 games for $48 add up quite nicely. Totally worth it IMO and anyone who purchases games on a regular basis and likes saving money should absolutely be a BB GCU member.