The reason I do not use this website too much is because too many threads end up going off topic just like this one. I find that very annoying. This thread started with the topic someone wanting to sell a half-finished house now its gone on to the strength of the Baht against the pound / dollar or Thai politics. Every thread seems to end up going in all directions.
Back to thread ... unless you get an excellent price Takiap, the advice to try to finish the electrics and water - then move in to bedroom / toilet until you can get the rest done seems best bet to me. The banks (Thai) might be able to help you also. Good luck.
Advice on selling unfinished home
It should be pointed out that most houses in HuaHin are sold before they are finished. Takiap could get an 'artists impression' of how the house will look when it is finished, then put it on the market as if it were finished. He could then take a deposit from a buyer and pay his builder to finish off the work. All the other developers do this so why not?