Good Medium Format Cameras Very Informative For A Novice. What Is A Good, Inexpensive, Medium Format Camera?

What is a good, inexpensive, medium format camera? - good medium format cameras very informative for a novice.

I already have a Holga, but I was looking for something more "professional", in,
Check opening times
Shutter
TLR and SLR or rangefinders place of the hearing.

I am a student, so they did very poorly, so I want something in the range of 0 - $ 50.

Suggestions?