Cost of coin + cost of slabbing + ebay & paypal fees = the mark up. Slabbers think that if a coin is in a graded holder that will mean an easy sell at whatever Price it's listed at, but what they don't seem to realised is that only the finest will realise that premium, the fact CGS is a British targeted market only will make it equally difficult to sell As there's not a huge following of their slabs or slabs in general in the UK market.