"You bought it good at that price." This should be "You got a good price on that" or "you bought that for a good price" or "you got a good deal on that". "We have to make do with what we brought along. " This is good. "I'll give you some food for you to take along." This is good. "I'll give you some food for you taking along." This is grammatically incorrect. You could say "I'll give you some food for taking along.", but I think "I'll give you some food for you to take along" sounds better. I think the most natural way is to just say "I'll give you some food to take along", because the "for you" part is obvious!