If you haven't got the money and you need to do it use an agent I'm going to guess that the standard fee from Bangkok crowd is around $40,000 for the whole process including the three months and on immigrant owe to start off with and you can add on four or five thousand for a multi-entry Visa as well. If you've got the money yourself do it yourself. Both work fine
nip in , do the odd workshop and vanish, no time to denounce you .....and almost no-one will....they will cherish your input.........just ban cameras as a prerequierment