Dear Tom,
The next staged payment is due at the beginning of May. I am having some problems with my bank in that they use an intermediary to do the exchange from Euros/US Dollars to THB with a very poor exchange rate and it will add very significant extraneous costs to the purchase. The only way to reduce these costs is to remove the intermediary bank from the process. So I would like to send dollars or pounds sterling to your bank and get them to do the exchange, but I would like to find out what the exchange rate is. Could you find out what they use ie "The interbank rate for the day, or the interbank rate + a margin of *@ per cent". I would then wire transfer US dollars to your bank for conversion and deposit into your account. For the sums that we are talking about they should provide a reasonably small spread on the interbank rate.