When you say all, do you mean a newer clean 4100, too?
Look, here's the deal......
All these units you are talking about here are 30 years or more old. They now need updating, recapping and bringing back to spec to benefit the full potential they have.
You can go out and snag a deal on a nice looking un-restored unit and possibly be actually be quite happy with it, however you will never know just how good they are until it has been worked on and brought back to spec.
We are just giving you the full story so you don't have great expectations and are then let down by poor performance from something that is over 30 years old and not performing to spec.
There is NO real way to get into McIntosh in a "cheap and cheerful" way, it is high end gear and it is more expensive than most other gear, its just the way it is.....second hand McIntosh gear holds its value because it is built to last and sounds incredible when performing to spec.
You might fluke a deal from deceased estate or something, but even then, with a C32 for example, expect to spend anywhere between 300-400 to get it sorted out....
Your budget for a C33,34 would need to be over 1K and then another 3-400 to sort it and bring it back up to or better than factory spec.
A C32 is cheaper but will still cost about the same to have the work done....
Or, do what I did and buy a C32 which has already had the work done, but then you will pay a premium for a properly working unit.....
I don't know how else to explain it...... otherwise you will think you've got some great deal, then the problems will start, or you will be disappointed how it sounds...