I purchased a 1955 Speed Graphic with the 135 mm standard lens and the Fresnel ground glass back one year ago for $209 shipped.
It is in excellent condition, all working and the shutters are accurate.
I use it with the RH/8 back and medium format lenses.

After a lifetime using slr, I find it difficult to operate especially hand held, I usually mess up some shots per roll by incorrectly sequencing shutter dark slide and film winder

here it is with a Computar 105 ~150 mm variable focal lens which is adapted via a home machined lens board