From experience Phuket and BKK is bit expensive punt there, i went to Pattaya few months ago. I find it cheaper searching through app as you can nego abit. Use wechat, thailove, Tinder Line is the best way to find. All kind of young to old girls. ST- 1500-3000bht LT- 2500-5000bht.
Food/shopping is bit expensive there. Finding st food is bit cheaper but some are unhygienic. Hotel quite cheap if you book online through agoda/hotel.