As far as I knew too, all BP's were $24-$25 at TRU too.. Actually I think there's a number of posts bitching about it somewhere around here, but not sure where. Maybe in the price increase/decrease thread. I know around me they've been $25 all year at TRU at least.
Not that it doesn't suck of course... As a matter of fact, the BP's were $25 last year, because I know the HFG pack was $25 when I bought it actually... Maybe the $20 ones you got were on sale or something? TRU doesn't set prices on a store-by-store basis to the best of my knowledge.