How do model shops make money on ebay

[daz75]

I find some of the prices baffling on eBay, I'm clearing out all my dad's old stuff, and check whats for sale before putting it up.

For example just sold a part for £3.99 as jemodels had it on at £4.26 with free posting
So take into account this has cost me nothing to buy, the cost to post was £2.80 plus Jiffy bag etc so call it £3 then minus 10% eBay and 3.6% paypal which leaves about 45p profit

So obviously the shop will have had to buy this at trade meaning surely they are loosing money by using ebay, all very strange