When I researched housing prices in the nice areas of Saigon in 2018, 50 square meter 1 bedroom apartments were sold at $300,000+. And "sold" here means you rent it perpetually from the development company to circumvent that 50-year land ownership limit. But that can put you at risk in case said company folds.
Oh and I've also heard a lot of stories about Vietnamese women becoming rather disenchanted of hip cool American backpackers, the latter of which presumably read articles like this and decided to try their luck. The backpacker area of Saigon is considered more like a slum that you try to avoid at night.
One other thing that the article dangerously omits is the fact that food hygiene and/or safety testing is still pretty much non-existent even in the richest parts of Vietnam. If you're old, a bad food poisoning could well kill you. And in Vietnam, you'll probably have one per year. That said, food is super tasty and impossibly cheap.