Does 50MM Summitar collapse OK on R2? Lens price?

[scottgee1]

Subject line pretty much sums up my questions.

Want to make sure either can fully, safely collapse into an R2.

Dealer is offering a very clean Summitar with a recent CLA.

Also, an Elmar f/2.8 (1958-1974 version) with minor marks on the front element but fine otherwise.

What would be a fair prices for these lenses?

Or should I just forget Leica and get a J8?

TIA!/ScottGee1