I do not have this problem - although I start to do more research and hesitate on the "buy" button when the price gets over $10.
But for anything under $10, if I think I need it then I'll buy it. Most of my iPhone apps cost money - I don't actually have that many free ones. Things like 1Password, TripIt Pro, 64-bit calculator, Endomondo Pro, Scan+ and others... I paid for them all.
On the other hand, I'm not much for buying things in-game. So for Plants vs. Zombies 2, I'd have happily spent $5 on the app (maybe even $9 or, with some thought, $10), but I won't buy gems or jewels or gold or whatever in game no matter what. So the PvZ2 guys totally missed my demographic - because I got a game that I would have paid $5 for for free, but I won't spend any money on gems or such in the game itself.