There is no minimum income requirement for the DTV - workcation option. The DTV Soft power option is via courses such as Muay Thai, cooking or medical treatment. You can be approved with low online income and substantial savings; Savings shows financial independence, so it is a plus. When i applied for my DTV, i had low online income at the time but got approved as i used savings to show i can live independently.
There are law firms/agents who do not follow the correct protocol for DTV applications and applicants have had their DTVs revoked on arrival, cancelled etc. Embassies have clocked on to applications via agents.
Others done similar to you and had their DTV cancelled or revoked and given a year ban from entering Thailand. The agent is doing business with you, she is not going to honestly tell you about the failures.
Anonymous participant There is no minimum income requirement. You should first contact the embassy you are applying from regarding your parents' sponsorship to see if they accept it.