Daniel
Choices are really dependant on format. For 6X6 (or 6X45), there are lots of options - Rollei, Kindermann, Leica Prados etc. You should be able to find a nice Kindermann for less than $200 - a nice Hasselblad will be over $1000.
For 6X7, the choices are far fewer - Goestchmann (very expesive but beautiful), older Linhof/Leica or Cabin (distributed by Mamiya and available new). A Cabin in good shape will be around $600. It works fine, but it is a lot of money.... If possible, stick to 6X6; alternatively, you are definitely in for some expense.