What you need to do is to apply for the PayPal DEBIT card ...this way you can use it stricktly for buying for your business , however it is the same as a visa or mastercard so wholesalers will accept it.
You can keep better track of what you spend BUYING merchandise and what your profit is. If I don't have the money in that pp account then I DO NOT BUY. It is the same as using cash. To run up a credit card to buy merchandise to sell is just pure crazy ...you will be paying interest so anything you make is not REALLY a profit unless you pay that card off immediately.