When you buy an account, on the checkout page there will be an option to buy insurance for a fee. As one might expect - PA doesn't offer insurance on accounts deemed (by their standards) to be risky.
In general, buying insurance is a gamble that is not in your favour (insurance/warranties are meant to be profitable for the company.) If the purchase was a relatively small amount you're usually better off not buying it - as the amount of money spend isn't worth the slim chance of the account being recovered. However if this is a high value or personally important purchase, you might decide to buy insurance so you're 100% covered.
Keep in mind you'll have to prove the account was actually stolen in order to successfully receive the PA credit. If insurance isn't offered on an account your best bet is to find a new account seller.