bb's are around 10 bucks a bag for bbbastards (best brand imo). But you will have to find someone that sells them or buy them from a store.
From the sound of it I dont think you really know how airsoft games work. We (or the host) arranges a deal with a paintball venue. We bring our own bb's and everything. The venue has nothing to do with airsoft rentals, equipment rentals or sales of bb's.
TM MP5k PDW -ris, stubby grip, DNTC, electro
KWA USP 45
"SNIPER" is NOT a gun. It is a person. Saying "I use a sniper" is like saying "I fly a pilot".