Hi SG
Not so easy to own a house in LOS as Thai laws are very protective (and I can understand that, it would be an economical invasion if they were not).
I suggest you try this link about the differents ways to own something.
http://www.siamnordic.com/eng_index2.htm
Abot the prices, I dont know too much except you can buy a house with oe living room, 2 bedrooms (1 with A/C), a nice kitchen and a bathroom for 1 million baths. 10-15 minutes walk from the beach.