So I'm looking at doing our own mocap using budget hardware, like a Rokoko or maybe another tier up from there. 

My main question/concern is motion actors, who would be good at doing that.  I live in a tech hub I was able to track down a couple and get some rates.  They seemed quite high.

I happen to have a wife who is a professional dancer/entertainer, and through her I have access to literally some of the best talent out there in that area.  And I'm pretty sure I could hire from that pool at half the cost these mocap actors wanted.  I'm having a hard time believing it's really that specialized, it seems to me more like they are taking advantage of very limited competition.

In any case who would you go after to do the acting on a budget?

An actor is only as good as the director.  Do you have an exact and complete list of actions that need to be captured?  Do you have a good intuition for the capabilities and limitations of the equipment?  Do you know how to get a good performance out of an actor?

If you own the equipment, then the cheapest way is to try to do the mocap yourself or with a family member.  You might still need to hire third-party talent eventually, but you'll have a better idea of what you are looking for and how to get the best performance out of your actor.

If you have to rent the equipment, then think carefully how the money you save by not hiring a mocap specialist weighs against the cost of getting a mocap newbie up to speed.