Not really... if you write an app that's native, then in-app purchases are controlled by Apple and they get a 30% cut of those sales. If you build an app using UIWebView then you could by pass those in-app purchases and get 100% of the sale.
1) A year ago Apple rejected one of our app updates because a webview inside the app had a payment form. (They told us that they do not allow any other payment option other than Apple in app purchases)
2) Yesterday they rejected yet another update for our app because it had a form where users could enter bonus codes.
ref: https://developer.apple.com/appstore/in-app-purchase/index.h...