How risky is contract selling when it comes to properties?

[BuildNSell]

There are a few houses I noticed that popped up on the local market with a contract attached to them. They would be sold to whoever buys the homes but they are unfinished so the contract stipulates that the company billed to finish construction would be paid to complete the home when it does sell. I would imagine this falls under wholesaling but I am not entirely sure, it is not a common thing in my area.