Each pack of 20 is £4, that's just 20p each!
Each card is 250mm x 185mm, glossy photo on the front and lots of information / details on the back.
Postage for multiple packs;
U.K. £1.50 + £0.50 for each additional pack.
E.U. £3.00 + £1.00 for each additional pack
Rest of World £4.00 + £1.50 for each additional pack