Xtreme Tactics in Manitoba used to sell bulk Airsoft Elite BB's in "Rice bags". Not sure if they do it anymore, but that said the shipping costs are phenomenal and just not worth it. When Metal Tech Mfg (The Tac Shop) used to do it they sold 5 bags in "bulk" for cheaper.
Other than that, IMO you should just eat the costs and accept it. Compared to paintball, BB's are pennies on the dollar.
Finally, the last thing you could do is become a dealer with Airsoft Elite or find one of their dealers and see if you can order x amount of BB's for cheaper (a minimum order quantity every quarter might be required though).
ಠ_ಠLess QQ more Pew Pew
READY TO >> RACE