I never said it was right or wrong - thats simply the system that is in place for listing charity auctions & as with every other eBay policy it should be adhered to until such time as it changes, or until eBay_UK has its own specific policy.
As for fee taken by missionfish - maybe $3 seems steep, but certainly the 2.9% is not nearly as much as some of these charities take - I found one the other day who "passed on" 56.9p of every £1 donated....rest being for "admin"
$3.00 is approx. £1.56 at current exchange rates...
Therefore - lets say you sell an item through missionfish, giving 100% to charity..
Item fetches £10.00 , 2.9% (29pence) to MF, £1.56 to MF - that leaves a charity donation of £8.15, so thats 81.5p of every £££ .... a much higher amount than many charities already take themselves - some charities will then take a percentage of that donation too, if its the one I found the other day ... 56.9p of every £1 - then approx. only £4.64 of every £10.00 raised selling through eBay goes to charity...
Thats not counting the listing fee & FVF which have to be paid to eBay... Time they are factored in - less than £4.00 of the original £10.00 could actually go to where it is needed most (more extreme example - most charities are between 70p and 95p in every pound, with varying admin expenses)...
You would actually be far far far better selling your item on eBay, forgetting to mention a charitable donation at all and simply donating the proceeds to a nominated charity of your choice.