Where they are based their target market is probably 90% Retirement and Spouse visas. Same as some of the well known Pattaya Agents most of whom will not touch DTV.
Anonymous participant crazy price. There are better options around. Issa Compass charge 18k and that is money back guarantee. It includes the 10k fee too. Siam Legal was about 400USD if I remember. Do it yourself
SerenePineapple9021 The minimum salary required for a Work Permit in Thailand for a Vietnamese Citizens is 25,000 THB a month so you exceed that amount (I know you are going for DTV but giving the figure for reference)
Mention that in any covering letter for your next application. Good luck
As the other poster said - Embassy dependent. Why not state where you are applying and ask what their requirements are? It helps people to help you and you get a better answer.