I assume you are talking about a spouse visa. You need letter from your embassy confirming the source of funds. Or you can deposit THB 400k in a thai bank account but you need to show this for the past 3 months plus a letter from the bank. And that is not all. It requires a lot more documents such as house book, rental contracts, pictures with you and wife/kid inside and outside the house and maybe more.... if you are over 50, you can apply non OA which requires 800k.
yes there might be cases like that. But this i think are rare exceptions. The German government for example offered stranded people a ticket home for EUR 100 (with obviously more extra cost after returning home), however I know of a few guys who are still here and enjoying it.... for those, time to go home I think. And then again, sorry to say, if you embarked on a journey by early / mid March and if you are not totally ignorant about what was going on in Asia at that time...you should have known the risk.
I think this amnesty was meant for people on vacation and caught by the sudden closure of airspace and borders. The Thai government has been very generous to give 4 months of visa extension FOR FREE. FYI an extension of stay is chargeable, people who have a legitimate reason to stay in the Kingdom need to pay THB 1900 for it. Almost all nations had repatriation flights organized so whoever is still here without a valid reason, sorry to say but I dont think it is because of cancelled flights. I think its time to go home for everyone who doesn't belong here, don't you think??