another consideration is how restrictive the experimental operating
limitations are.

many experimental - racing/exhibition operating limitaitons from "back
in the day" are quite unrestrictive and literally worth their weight
in unobtanium.

however if you take your Ka6 or otherwise semi-common type certified
glider and put it into the experimental - racing/exhibition category
in the modern era it will have restrictions that involve faxing FSDO's
annual letters and getting special permission to operate more than X
miles from home. These in and of itself aren't too tough to deal with
but as a buyer why would I want the hassle when there are plenty of
other non-restricted gliders out there available to buy?

I own 3 experimental - amatuer builts which I thoroughly enjoy.
However the restrictions on them are no where near as restrictive as
experimental - racing/exhibition.