Ask 10 agents and you'll get 10 different answers. They just have a format that is presumably relatively successful (although not always!) and they'll stick to that. I found the same thing for my now ex, one even suggested dumping a large amount of money into her account which I've always read as a big no no. Others said they wouldn't use the statements and others suggested something like 30k being in there, going up over a few months. If you use an agent make sure they are OISC registered as they should at least act to some sort of professional standards. Some of them will just ask you for some documents from you both then write everything themselves, you will never see what's written except briefly at the Trendy in Bangkok when she scans them in, before the files are taken away again. This means you are tied to them in future as you actually have little idea what was said on the application and in the letters written pretending to be you. I heard about a guy who's girlfriend used a Thai bloke on Facebook, it wasn't cheap either, and the rejection letter read like they were talking about somebody else and the agent just said he'll do it again but he still wouldn't share what was written. I can only imagine what the letters pretending to be the farang read like if the Thai "agent" didn't have a native speaker doing them for him.