That's true. There's a big difference between "expensive for Texas" and expensive on the west coast or in NYC. Still, a house or apartment in downtown Dallas (where the homeless folks are living) is nowhere near $150k.
I'm not sure what's causation, and what's merely coincidence, when it comes to "expensive places have more homeless people". It may just be that density correlates with both for a variety of reasons. If you don't have transportation and need to eat every day, being in a metropolitan area is pretty much mandatory. Those also happen to be the most expensive to live in.
I'm sure that's true of Houston, Indianapolis, Detroit, Tulsa, etc. However, I think there's some unique elements in SF beyond just being an expensive city.
I'm not sure what's causation, and what's merely coincidence, when it comes to "expensive places have more homeless people". It may just be that density correlates with both for a variety of reasons. If you don't have transportation and need to eat every day, being in a metropolitan area is pretty much mandatory. Those also happen to be the most expensive to live in.