Remember you are protected by the Money Back Guarantee, and the seller doesn't get much say in the Dispute.
You have 30 days from delivery to open a Dispute .
He can pay for Return Shipping and refund you.
He can accept a returned purchase and refund you.
He can refuse a returned purchase and refund you.
You are also covered by Paypal's Buyer Protection for 180 days from payment and by the credit card you use to back your Paypal account.