So I just purchased the Nether Realm expansion from ebay (for £50!) and was disappointed to open it and find that it doesn't appear to be genuine! The cards are not linen backed and have been printed slightly off centre. Have I been sold an imitation pack the seller has had made or is this the way the Nether Realm expansion was sold?

The Nether Realm and Deep Realms were printed by FFG's Print on Demand service, which means it is printed on different card than the mass-produced expansions.

Ah that's ok then. Thanks for the response.