MonkeyDragon
Explorer
I don't think raising people from the dead should be just cash. There should always be consequences!
Ditto that, and when I started my newest campaign, I didn't want raising the dead to be like paying a parking ticket. However, I also didn't want to limit my player's access to that magic, because I would rather encourage them to stick with characters they've developed.
What I decided was that any time someone is brought back from the dead, they must agree to perform a favor for their god (or god of their alignment, if they don't have a specific patron) in return for being allowed to go back. In my case, the favor isn't meant to be a trick. It's a task that is possible for the PC to complete (possibly needing help), and they have a year and a day to get it done.
In the OPs case, I LOVE the idea of the possessed PC wreaking havoc, and the bargains of hunting vampires or making sacrifices. The only thing I would be cautious with is trying not to screw with the party TOO much, or they might shy away from making such attempts in the future, and it's a great roleplaying opportunity.