The Ricoh lens sounds like an interesting option for something like Kinograph, where you might ship the machine to people and using new components is the right thing to do. It certainly beats the Schneider in price (new) at about 600€ vs. 900€ (just a quick Google search). Only needing extension tubes would also make for a simpler setup than adapting the Schneider lens.
The Tamron lens @matthewepler bought would probably be enough for most 1080p scans, though. At 180$ new it is obviously much cheaper than both the Schneider and the Ricoh. But for 4K scans I think you need something sharper, such as the Ricoh or the Schneider.
That said, I think the used price of the Schneider (and other enlarger lenses) at 50€ to 100€ is hard to beat and probably the preferable option when putting together a scanner for yourself. Even the cheap (but also much worse) lenses you can buy for the Raspberry Pi HQ Camera cost almost as much.