I got the AA holder for mine off eBay for £20 or £25 .
I already had one , but misplaced it amongst everything else .
So I gave up looking and bought another .
They were easy to find and no too expensive to be better off looking for my old one .
I certainly wouldn't pay £100 for a battery holder , I didn't pay that for the whole camera , and it came with the battery holder !
I bought the grip separately.
You could possibly buy a complete, but faulty camera for the battery holder , and then sell the camera on .
There's a complete one on eBay for £90 , but it's not clear what the fault is .
It's listed as faulty battery grip , it might be the camera body at fault rather than the battery insert .
In which case you could sell in the body for £70-£80 and the battery pack won't cost you much more than the import duties of your country .
Certainly worth looking into.
Find many great new & used options and get the best deals for Nikon F100 35mm SLR Film Camera Body Only at the best online prices at eBay UK! Free delivery for many products!
www.ebay.co.uk