Don't know about sales in Texas, but in SW Florida folks aren't selling out. We are not ready to purchase yet but thought we would just investigate some neighborhoods for future references.
For a owner-owned lot for a decent sized park model to sit on we are finding prices from $90,000 to well over $200,000. You can cut that in half if you want to purchase in a park where you don't own your lot and pay $700 or more a month in rent.
We went through a couple parks and only found one or two units even for sale. I suspect baby-boomers are still retiring to Florida in record numbers.