The buyer could be new and be restricted to the amount of spends on eBay.
The buyer could be in a country you do not ship to.
The buyer could have unpaid items strikes that if you have your blanket blocks set will prevent the bid/buy.
eBay normally advise a buyer of the reason for a bid not being accepted - ask your buyer what message they get.
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I have been imported from Australia and this is my posting ID
