My votes for Mr Cad's Japanese made view-finders. These are labelled "Helios" because they were sold by a UK firm to go on the USSR cameras they sold some years ago. I've used one for ages on all my screw thread cameras, Leica, FED and Zorki and have no complaints (although the VIDOM is on the model II in the display cabinet).
I expect they appear all over the world with other names on them...
An original Leica VF would be great or the 35m lens with the goggles but the question was about doing it on a budget.
Regards, David