re Durst
Get ALL the parts when you get the enlarger.
Because Durst is out of the enlarger business, you are completely dependent on the secondary/used market for parts.
I'm still gathering missing parts for my L1000, and that has taken a LOT of time, effort and extra cost. And yes some parts are VERY VERY difficult to find, and EXPENSIVE when you do find it.
You will pay a premium for individual parts vs. getting it all with the enlarger. ESPECIALLY the condenser lenses. There are guys out there taking these enlargers apart to sell the pieces individually. If you are not careful, you can easily double or triple the cost of the enlarger when you have to replace missing parts.

This also applies to Omegas and Besslers, but to a much lesser degree.

If you are not buying new, get the enlarger as complete as you can, to minimize the cost of replacing missing parts.
The cost of replacement parts could turn what you thought was a great deal into a BUST.