I have bought two Deardorffs on Ebay in the last year. I disassembled, stripped and refinished the wood and metal as well as replacing the bellows. The bellows cost $290.00 on each of the cameras. The refinishing materials were relatively inexpensive. On each of the cameras, that I bought, the bases had developed splits (due to the way in which Deardorffs were built. I disassembled the wood bases in the process of rebuilding the cameras, reglued and rebuilt them. I would not be reluctant to try another camera again. The bellows are something that I think that I would at least try to build myself next time. Most of the cost of replacement bellows has to be the labor to fabricate them. There are sites on the internet that discuss materials and patterns of bellows construction.
For those who have an inclination to rebuild cameras, I would get the seller to confirm that the rack and pinions were in good shape. That all of the movements worked and that there were no broken or missing parts. The greatest majority of the metal on these cameras is OEM and is very costly to have fabricated unless a person has a metal mill and lathe.
Depending on a persons woodworking skills, the thing that has appealed to me is to take 8X10 cameras and building new backs for 11X14 format, 8X20, or even 7X17 format. There seems to be a relative shortage of ULF equipment on the used market and new is costly. There is an apparent resurgence of alternative process that requires contact processing and the cost disparity between new ULF and what could be accomplished through conversion might make this a viable market.