Look for something like Balda. I just got a Balda Super Baldax from a Dealer, had a CLA, and working perfectly, comes with coupled rangefinder, and paid 59 GBP, also the Ensign Selfix range, with the wonderful Ross express lens, terrific cameras, I have 3, including a 820, and paid under a 100GBP for each one, they are all working perfectly, no rangefinder with them, but you can pick up shoe mounted rangefinders 10 to 15, I have a Ikonta B, again very simple but a great lens, and paid under 30 for it, and I am just looking at some of my personal collection of working folders that are in use all the time, I have never paid more than 90 for any, and that was for an Ensign Commando, 1948, built in rangefinder and uncoated lens in perfect working order, and all from dealers, so you do not have to pay an arm and a leg for MF, just look around,
Richard