I imagine it's the same companies hiring freelancers off Upwork and other such sites. They're looking for the cheapest possible labor, and quality comes second.
I must be sheltered in my corporate job, but I can't imagine companies shelling out half a years programming wages for yet another messaging app. I can't think of the use case for a one off messaging app that isn't fulfilled by the plethora of existing options.
1. Their app demo pricing is a guideline for the cost of a typical app in that space. People aren't all going to Gigster for the next Snapchat or Yelp clone. They have specific problems and Gigster makes specific solutions.
2. I've also worked in a corporate job, and 40-50k is not a lot of money. We spend that sort of money on software license requests without blinking. 50k for a fully baked, semi-functionally software project is a bargain.