Mobile Paypal is the stupidest site ever. You cannot do anything on it and worst of all, they is no way you can opt out and go to the full site!
I already hate the way paypal fingers sellers on ebay so I am not pulling any punches here.
Every paypal transaction incurs a fee to the seller, it is like a 3% tax, then there is the ebay fees to follow.
For ebay sellers, the best thing to do is avoid using paypal altogether. Advising buyers that they will have their money refunded or the postage of their item will be seriously delayed if they want to use paypal service.