I am currently in the process of a similar rebuild project.
The 13000$ overhaul price is somewhat optimistic in my opinion, I just zeroed my engine and being an AME (Canadian version of the A&P but more refined :p) my costs are above 10000$ and I don't have to pay for my labor.... or turn a profit or carry an expensive insurance to cover liability.
The time and energy spent on these projects is quite enormous... I don't think it's worth it in this case.... right now the market is tanking and the airplane will not sell easily. Buy a flying airplane...it is cheaper.
