Under $250, Yashicaflex, 124 or Ds are a lot less, Minoltacord, Rolleicord, Mamyia Press 23 with standard lens, early Bronica with standard lens and film back, Kowa 66 with 85 2.8 the Supers might run over $250, Mamyia, Pentax, 645 SLRs with standard lens, RB67 maybe lower end with standard lens and film back. In the $250 to $500 range, Mamyia Universal with standard lens and back, ugly Hassy, Kowa super 66 with back and standard lens, better quality RB 67, Rolleiflex with 3.5 Tessors, Rollie 66, maybe, later Bronica with lens backs. There are many more systems, Fuji fixed lens MF cameras are a good buy.
My complete Kowa system, Kowa 66 and supper 66 bodies, WL and eye level finders, 55, 85, 150 and 250 lens, total in todays dollars, around $2000 or less. My Mamyia Universal, 2 bodies, 3 backs, 65, 100, 140 less than $1200.