If you want one then go for it. Getting one from the C-store means you get it now ... right now. And only costs $3.00. That is half the cost of most fast food meals or a few cents more than burger/fries/coke from a value meal.
Sure, there are better weapons ... don't worry about that. Why? Because you want it. Just do it
I was seriously disappointed with this one too. I really loved the idea of weapons packs being introduced given the TR-116 pre-order or the weapons we could pick up in FE's and such, but how much they were charging for how little you got really made the whole thing a waste. I can see why they never went back to it, but sadly if they would lower the price as well as raise the value of the weapons (either in stats or number of skins or weapons) than I could definitely see myself buying into these.