Couldn't agree more. Many agents are actually way below $400, and they still guarantee you success in getting your DTV. Some people will just do all they can to spread false rumors here.
"If you don't qualify an agent is going to magically get you a DTV." Well, you are criticizing those who'd need an agent for not being able to input their own name accurately, but look at your own sentence. You obviously wanted to say the opposite, so... Application denied? Anyway, there are plenty of reasons for being denied or having your application cancelled, some might be obvious, others much less, and agents are usually experts in optimizing your chances of being successful. A waste of money? Well, for some, maybe, but each case/person is different, and depending on what country you're applying from (especially non-English countries), it can be really tricky to deal with all the translations, cover letter, portfolio... I'm well aware none of what I say will change your mind, and I actually couldn't care less. I'm just voicing my opinion on the matter.
Participant anonyme 419 and why so? Some agents even guarantee you to obtain your DTV successfully, and quickly (usually without losing time being asked to provide more documents after submitting your application), for very affordable prices. Many people here reported losing more money on having to apply a second, or even a third time, because embassies are getting stricter and stricter about it, rather than spending a little extra for a good agent that will ensure you get approved. Got mine in 3 days, Hanoi, SP (cooking), in one shot, and absolutely no regret paying an agent for it. To each their own, obviously.
I paid 15k THB for their 6-month course. I go there just once a month, this won't make me become a 'chef', obviously, but it's fun nonetheless, and it got me the DTV anyway.
Well, you can get it extended here, in Thailand, but... you probably don't want to go through the hassle and stress of doing the extension locally, at your nearest immigration centre. They'd ask for a pile of documents and updated statements that can be hard to get. It seems to be MUCH easier to simply travel outside of Thailand and then back in, you'd get a new stamp for 6 additional months, in less than a minute.
Just go the 'easy' way and contact ISSA Compass visa agency. I don't work for them, but they've been super helpful for me to obtain my DTV, 2 months ago. From Hanoi as well, but using Soft Power (Cooking school).
Participant anonyme 547 best solution indeed. Got mine easily in just a few days, 2 months ago (Hanoi embassy). And they're also much cheaper than most other agents as well.