I hate to give you a wobbly answer but... It is a matter of what you think it is worth.

With that said, you have to balance the market value of an unfinished kit, the current cost of a kit, quality of work completed and the completeness of the kit (all pieces and construction manual available), also, completeness of work logs and paperwork for transfer of ownership. Usually the work done by the current owner doesn't have much value.

When I sold my partially completed kit (RV9), I priced it for the value of the parts purchased and feel I ended up on top. I have had friends buy partially built kits, expecting a quick build, but they had to undo much of the work to bring it up to an acceptable level.

Ralph