Seller sounds like they got a bit of a raw deal having received bad feedback on this. They stated in the auction postage would cost £2.80 right? So everyone knew the cost of delivery before bidding, then its up to the bidders to decide their top bid.
The seller then posted the item as a large letter and not a small parcel, so here's the rough breakdown of their actual costs...
2nd class Large letter stamp = £0.74
Padded jiffy envelope = £0.69
Packing tape, figure bag, etc = £0.10
Paypals 5% charge on P&P = £0.14
Total = £1.67
So all in all the seller perhaps overcharged by £1 (that's assuming there was no petrol/time costs to make a special trip to the post office), which some sellers will refund, some others won't, but as a buyer I wouldn't expect to get overcharged postage refunded, because I knew the cost before bidding. If the seller decides to refund the postage, then they obviously deserve exceptional feedback, but IMO no-one deserves to receive negative feedback for a slight overcharge in postage.
I would also say that anytime a figure is described as having any kind of 'wear and tear', then do not expect to receive anything less than an item that is well and truly used.
Slow or no communication from sellers is a valid gripe though, because if they have taken the time to list items, then it is their obligation to ensure the buyer is satisfied. Waiting a couple of days to receive comms is fine, waiting weeks is not!