What would be a fair asking price for both a UG Class and U Class by OO Works. I bought these a couple of years after production was exhausted but they were able to build me what they described as the last one ever to leave the assembly line. So much so, that the UG was not lined, numbered or transferred. Simple black finish. Both are boxed as new and never been on a layout for more than a few hours running and returned to their boxes.
I would certainly think consider a sensible offer for both of them, but not split.