Hi all,
At least in the UK, Hasselblad wants 140 pounds for a new battery (confirmed with Calumet earlier this week). I found out that the Sony NP-F570 is the exact same model and fully compatible with the back, and can be had for 17-25 pounds.
So if you need more batteries, no need to go the Hasselblad route.
Hope this helps!
P.S: If this is general knowledge, MODs please feel free to delete this thread.