So you'd be buying an unimplemented, unpatentable idea for $20k that a dev could build in a month (for presumably much less than $20k)?
There's a million and one ways of doing things, the way patents work is a specific implementation.
Gaining a patent amounts to throwing stones at each other.
20k is a lot less than hiring a HR department and finding a developer. Haven't looked at the site, but was assuming some of the ideas have an MVP of some sorts.