Like anywhere in the world - if you visit the Busy places (Tourist destinations) you will pay for the convenience, razzle and dazzle, go to the "out of town places" (and so true in Thailand) you will be surprised how low the price is but don't expect lavish surrounds.. it may not like good but itis what on the inside that counts..
Cost of Food Pang Loy (stree vendor) food and most humble Thai resturants are incredible cheap price but sensational quality food... an example of the price see this forum article on Pang Loy food (about half way down the page is a picture of a plate of food with the price shown in baht (This example is in the Bangkok)
The price can be as high was you want according to the location and restaurant name (even the most expensive is by comparison much lower than another country)
Cost of Transport Public transport is so low it's not worthy worry about. I think it's about 200baht for a Bus from Bangkok to Pattaya (that's about 2+hrs) Even Taxi prices are very low.. Taxi from Bangkok to Pattaya 1.5 hrs about 800baht to 1100baht (haggle)
Cost of Accommodation Price can be from 200baht but for hat it's very basic thai style (no complaints if you can handle that style) but to be realistic you should be pitching from a minimum of 600baht for a very basic room and a very basic hotel.
Here is a list of forum articles with tag word accommodation (the 2 in bangkok include prices).
The 5 star International Hotels are going to be more like 4000baht per room... but to get a better idea just visit the travel thailand website, select an area and see the info about accommodation and the link therein to pricing.