I use Design and translation services
yes I know but services cost is not fixed because that I can not use in-app
As I know, if the item is a physical one it is ok to use paypal but if it is a digital item like a service , why would apple allow you to use paypal instead of their own payments service ? They will lose %30 when you use apple. So everyboday can use paypal to avoid %30 apple fee. The rule is clear at guidelines of apple :
Apps may not include buttons, external links, or other calls to action that direct customers to purchasing mechanisms other than IAP.
if you post the rejection message by Apple here , we can understand better the rejection. But what you say doesnt make any sense to me. Anybody can say , my price is not fixed for any service to avoid %30 fee. Apple will probably not accept it. but as i said , post the rejection msg , we can understand better.