When I had a paid app in the app store price didn't seem matter too much.

I had a free version of the app with IAP and a paid version. Both initially cost $0.99 but after 6 months I raised the price to $1.99. Sales actually went up. I think if you have an app people like and you have good reviews, price isn't as important.

Graph for paid app https://www.dropbox.com/s/s7zvicfuan9ci5n/paid.png?m

Graph for IAP https://www.dropbox.com/s/3ddr15si5qp5bux/iap.png?m