Anything is possible, but as noted above, love and romance here is not often the same as the Western World - the word practicality has been used and this is mostly correct. The other aspect that I did not see mentioned is that Westerners tend to hang on to the romantic notion of "love" that we all had as teenagers... there are not only cultural differences but age differences that come into play and I mean age differences in that the boyhood concept of love is not as prevalent in older people - that is for most, a time of life element that has passed.
I don't know how much finances is a requirement for everyone, but most Thai ladies are not really interested in an equal partner that they might end up supporting in times of illness. If you do prove yourself as a good supporter willing to take care of them and their family, they may come to love you and respect you, but again not in a teenage, moon, June, spoon way.
But, with minimum income, what will you do for health care? I have seen guys here who survive on little, living in Thai style apartments for $100 a month and eating cheap street food, but this lifestyle is not attractive for most Thai ladies. In many ways for poor Thai, it is still a matriarchal society and they look at having a husband as someone they need to take care of, and this should be compensated. One lady who wanted me to introduce her to a farang, after a moments thought, told me she didn't want a husband who needed too much care... [she did not ask for someone young or handsome or any of the things that most Westerners consider important. No mention of romance.
But, what do you want? Vietnam era would put you in your 70s or late 60s at best. Do you want a 70 year old lady? I know some fairly attractive late 50 year olds and even a few 60+ but they are not seeking the hard work of a farming life - what do you have to offer them? They do value kindness and goodness, but generosity too...