I didn't have my notes with me last time, so I couldn't actually remember how many MP's it takes to travel through time. Finding them, it takes me 2 MP. The problem is, that if I want to use any of my other gifts, except the gatemaker ones, they are all under my Domain and draw on the same MP pool if I want to add any penetration. So if I want my Sovereign's Gift to overcome any Auctoritas, I need to spend my possible time travel points on it..so I run out of them quickly...