200 to 500 bahts for Thai bank charges is not true, each bank charge whatever they want to charge on the day, I've never been charged 200 to 500 bahts for transferring from the UK.
They never show the transfer charge they just show the total per transaction available in the account, mine is always £40 (1700 bahts) less than expected & that's allowing for a lower bahts rate than showing in currency index.