I'm almost finished the game and have only just visited the store and purchased some clothes (bought the red hat for 200 points, and the red boots for 250)
You really don't need to buy clothes to complete the game, it's kind of like how other games offer to unlock all levels for an in app purchase, it's basically "pay for a cheat" like the X-ray googles would make the game so easy..they'd be no challenge at all.. So it's pretty pointless aiming/grinding for them..
I'm pretty sure I'll be able to complete the full game with just my 450 points worth of purchased clothes, I might need to grab the spots for 150 as well for speed, as it's starting to get very hard to make it on time. I still have many coins left over, and I really haven't even being trying to collect the coins..
So try not to focus on the store too much.. This is a wonderful game, it's a shame it's not getting more recognition.
Ps- thanks for reading my novel connector! ^_^