keeping recipts is one thing, what if you got something rare on the cheap? my 1858 small date farthing came with a card with the price of £5... no way would i be able to replace it at that. but yea use omnicoin, its a great place, i really do need to add up the total value of my collection, i know 3 or 4 of these coins are worth a fair chunk of the total value of my colelction (the 1858 farthing, 1939 rhodesia 6D, 1840 EF farthing = £120-150 alone)