Thank you both. According to the embassy here it's $1600, which is about 50,000 Baht. They also say Fast Track at the airport - is that a worthy benefit?
OK, thank you. Sadly, I don't know what increments are. The Americans will also pay directly to a Thai bank, I'm told. If you want to advise me the pros and cons of both, it would be very much appreciated. It's all knowledge that I need to gather.