Hiring a negotiator?

[Vonetta Booker]

When looking for off-MLS deals, I'm good at striking up a rapport with sellers--but not great at closing. I'm still learning the ins & outs of creative deal structuring, and I'm often worried that I may not be offering sellers the most options because I don't know about them or how to structure them & make them sound good to the seller.

I'm wondering if anyone's ever hired someone to negotiate the deal for them, say, as a partner--and then perhaps give them a cut once it closes?  Is that a thing? It's something I'm willing to explore as another area of delegation to a team member who's better in that particular area than I am--as a means of getting deals closed. 

If you've partnered up w/ someone to help close your deals w/ private sellers, how did you structure it & how did things work out?