I forget what I paid for my volunteer visa but I am sure it was quite a bit more. My marriage visa cost LOTS more (wife, immigration paperwork, marriage paperwork, blah blah blah).
65K is a great prices to stay in Thailand. 180/baht a day.
The two reasons EDU visa haven't appeal to me.
A) Tests, immigration monitored progress
B) It may raise flags when entering Thailand. I had an immigration officer once tell me the EDU visa, isn't the best option for someone like myself (48 years old).