the three places we look to be staying are

http://www.bangkok.com/amari-atrium/index.htm
http://www.samui-hotels.com/csvsamui/index.htm
http://www.phuket.com/merlinbeach/?

anyone been to any of these?

I'm sure Shirley will tell you more about the Central Samui Village. Costs- I haven't been to Thailand since easter last year but you will be surprised at how cheap it is to eat out. You can easily spend just £15 for dinner for the two of you. If you eat in the hotels then expect to pay a lot more. You can also spend a lot less for dinner!

Thailand is a wonderful place and the people are even better
i have just booked my 3rd trip in 3 years and love it, the 3 hotels you have
chosen look great choices

When you arrive you will find deals like this all over thailand

http://www.thebeachgarden.com/bbq.htm

a BBQ including seafood for less than 3 pounds per person and there
are other deals which are cheaper than this, although popular hotel
meals and tourist areas charge much more

you will love it

I stayed at the Cental Samui Village last July and it was lovely, I do think the location was very far out but the hotel courtesy bus is very good and regular and goes to Lamai and Chaweng every night.
The rooms are lovely , very spacious bungalow style and the breakfast is a really good buffet, we had lunch every day and it was reasonably priced, there are lots of steps throughout to walk off the calories.
The 3 pools are really nice and sunbeds always available, the 2 higher up pools are lovely and quiet but the beach if I'm being honest is not up to much , hope this helps, any questions please ask, shirleyv