According to guidelines iap is just for digital goods not physical goods. I would love to give my %30 to apple but as long as i read , they dont accept it.
Can I use webview to show for example paypals billing page and they accept it ?
may I suggest you have a look at 'zooz', we integrated it successfully into the android version of our app (there is an excellent library) and I think it should work in iOS too. Drop me an email if you want to see a sample. Zooz is really good and very quick for the user to use which helps a lot to encourage sales. Best part though you can bypass the fees that apple would throw on which are insane