I've got a lot of medium format gear - all cheap. Top of your price range limit might be a Mamiya C330 or C220 if you are lucky on eBay. I've got one and yes they are great, but extra lenses start at £150 a throw. Still damn cheap for MF but maybe out of your range?
I had a Kiev 60 medium format camera from new. It was the invension of the devil. Cheap - but bl**dy awful! Don't touch. It was the body shutter that was really naff. After replacing it under warrenty twice I chopped it for a much older Pentacon 6 body, a much nicer camera. This has proved 100%, reliable but they are very old now, so maybe I was lucky. Point is, you then have access to a lot of cheap lenses, Zeiss Jena P6 lenses (excellent and reasonably priced) and also russian Kiev 60 lenses (not as bad as the cameras and cheap!)
If you don't need to change lenses there are lots of TLR bargains about, but nearly all will have standard 80mm lenses.
The chinese Seagull is nice and can be bought new for less than £200.
Ditto folding cameras. There are some nice Mamiya folders on eBay right now, 6 X 6 but they will all be 80 mm (0r 75).
You can get basic folding 6 x 6 cameras from about £15 in fair order. If you have a £200 budget you could get something really fine - a nice Zeiss Ikonta or something tasty, but you will always be stuck with a standard lens. I love them, but the more basic ones have no rangefinder or parrallex correction for the viewfinder so not so good for fast, quickly framed shots.
If you want wide angle and cheap I'd go for a Mamiya TLR.
I've never used a Bronica, but I bet they are cheap because there's so many ex-wedding photography pro cameras on the market. So...might be some very well used ones about - be careful. A seagull might be a basic amateur camera, but a warrenty is a nice thing to have ;-)