regionals is going to have electivire as a promo card. Most stores are going to want more money for packs individually. online is really one of your best places to get boosters at the best values.
I know a shop in California that sells packs for $2.50 each and boxes for $80. That seems like a good deal. (No shipping since I live near the shop:biggrin
I'm not sure if you live near here though.