I am sorry your ideas and opinions are are wrong the law is clear. And you are mixing issues this is an issue of a sale on ebay a legally binding contract.
I have done it and that's it. The person involved was represented by the citizans advice who told him he had to make good on his promiss and either supply the item or put me in a position so I could purchase one at the market rate. He concided that " he had learnt something" like you hopfully are.
Broken items a plague of locust or any event does not release the seller from his responsibilty to supply the goods.
The purchaser does not have to prove that the seller is 'deliberately'(what ever that means) not supplying the item only that he has not supplied it.
You are mixing issues intead of sticking to the facts of this specific post.
If one purchase a car and it gets stolen before recipt the person has to still supply the car. If they refund the money and that puts the person in the position they would have been had they recieved tha car that is fine.
But ( and this is the bit you are missing) if an auction takes place and an item is bid on and won at well under the market price ( a bargain) IE a lens that would cost £400 in a shop at the market rate is won at £200. Then the seller fails to supply the lens ( for any reason at all) and refunds the £200 the purchaser can sue (as I did) for loss of bargin at the value of £200. Which then puts the buyer in the position he would have been in had the contract been fullfilled by being able to buy the lens at £400 from the shop (no loss of bargain).
When one sues they sue on the prima facia (at first light) market value of the lens so if the lens is as above £400 in the shops or on the net their is no dificulty with detriming value because the prima facia price is that which is used to calculate the loss.
This is a big advantage because the seller in my case tried to dispute my valuation of the loss (difference between bargin price and market price) but he could not because the law said all I had to do was demonstrate the market value(the price in shops or on sale elsewhere) which I did by producing adverts from
MPB and other suppliers of that particular lens.
I sued because I contacted ebay about my loss of bargin and they did not make (and never do) any attempt compel the seller to honor his contract. It is a seperate issue but to my mind there is an issue with ebay here it could be argued that they are acting as an agent to protect non sellers.
If you do a search there are many complaints about people winning items on ebay at bargin prices and sellers failing to supply. Just because sellers are not getting the price they want at auction is not a valid reason for failure to supply the item. It is a breach of contract.
I hope this helps anyone.