I'm pulling out transformers from ceilings and have a box of them as spares but I used to buy them from ebay. They do seem to have gone up in price but 105ma is enough to drive a 50w halogen.
I used to use this brand but was getting three for this price:-
I’m just sorting it for a mate for nowt, I just want to replace the driver for now.
I wholeheartedly agree that GU10 spots would be better, but replacing all the spots rather than one driver is too much of a faff for me.
I’ll stick to fixing motors!