I have found myself drawn to the idea of using the cards produced for the game as a source of NPCs, Quests, Locations and Items all highly relevant to the Warhammer world.

The cost to buy the cards for *just* this purpose seems a bit prohibitive so I was curious if anyone can speak to them as a roleplay resource.

Never though of it, but I do own Warhammer Invasion and play it from time to time. It's quite a good game.

To use it as a resource for WFRP might be harder, I don't know exactly what you had in mind but here are my thoughs about different types of cards in the Warhammer Invasion box:

• Quest: Quite far from useful in a roleplaying sense. Sure, they have a title which might be used to inspire an adventure but otherwise the quest cards aren't closely related to roleplaying quest.
• Items: Quite few included (at least in the core box and the expansions I own) but they could easily be converted to WFRP and used as item cards. Many of the items are quite powerful though (such as runefangs etc.)
• NPCs: Most "creatures" in Warhammer Invasion are generic such as "spearmen", "slayers", "ironbreakers" and such. There are some hero characters included though, and I guess you could convert them to WFRP with some work. Almost all the creatures feature some great artwork though and could be used to show the players how someone look, some of the artwork is used in both WFRP and Warhammer Invasion.
• Tactics: Could be used as an inspiration for actions, but that would be a lot of work (and using Strange Eons is probably better when creating actions).

In general I'd say you'd have to want to play Warhammer Invasion to purchase the game, as I believe the uses for WFRP is limited. Mostly the artwork and some inspiration to create your own stuff.

The cards are of a different size than the WFRP cards as well (standard card game size rather than standard board game size).