I've got 3 right now, one of which will stay sealed in the package. I wouldn't mind another couple to open, but probably not at TRU's $20 price tag. So if they get marked down there (fat chance), or I come across a good deal on eBay or on the trading boards, I'll snag a few more. If not, then 3's my number.
Probably only going to get 2 of the Hoth 4-packs though, but I'd like several more of the orange astromech from it (again, fat chance).