Well, earlier this year I spent $200 on a CLA'd Perkeo II for traveling light -- so I guess I'd go that far.
I have some still-working Canon FD gear but am considering picking up an EOS-something body to share lenses with recently acquired "alternate technology." Alas, given the current plummeting state of my retirement nest egg, that will likely be on hold a while. I would think $300 to $400 wouldn't be out of line for that. By the time I've added accessories and spares, I've probably got at least twice that amount in the Bronica SQ-A I cobbled together in 2006.