If you plan to shoot IPSC, try TM superior grade 0.3g pellets. A good improvement in group size, but they're hella expensive or completely unavailable here. Typically bags of bbs are barely worth coming back with. They're heavy, occupy a lot of space, and they're cheap enough here. If it's bbs you want to come back with, get dense expensive ones that are really good.
Get yourself some hard to find spare parts for your collection. Dinky springs, firing pins for your GBB etc. The stuff that gets pranged or lost when you disassemble your guns or dry fire it too much.
Want nearly free GBB gas?