In ZeeXchange website it is written Gemstone as Natural/Enhanced this means that gemstone is Natural but it is treated (enhanced). The treatment is not mentioned there but most likely it is either heat treated or diffusion treatment. These kind of treatment can even turn white sapphire into blue sapphire, so paying $3,200 for a treated 2 carat stone is not worthy.
And, if someone is selling Ceylon Sapphire from Thailand then it is most likely heat of diffusion treated. Ceylon blue sapphires are actually mined in SriLanka so when you are purchasing Ceylon sapphire it should be untreated and its origin should be Ceylon, SriLanka, otherwise there is no use in buying a Ceylon blue sapphire.
I would suggest you to go to ebay.com to search for your blue sapphire and please avoid sellers from Thaliand (Bangkok).
I don’t know how trust worthy these ebay-sellers are but their blue sapphire looks pretty good for the price & quality: