Don't bother with eBay.
Contact the seller.
There was some sort of problem tonight with Paypal payments.
The seller may send you a new invoice.
Or she may decide the sale is more bother than it is worth.
But talk to her.
EBay has nothing to do with it.
Hmm- more to the point.
This seems to be a pickup and pay item.
Sellers are allowed to demand cash for these, and most experienced sellers would encourage them on that demand.
Your protection as a buyer is that you can examine the item before handing over your money and refuse to complete the sale if the item is not as described.
(It is very poor form to agree to a pickup and pay transaction and then try to haggle the price down. )