You want the unemployed to pay? Or do you want the employers to pay? If you want the employers to pay, how do you attract enough attractive unemployed to your site?
This suggest then that the relevance of any solution would need to appease the employers... yet here we are trying to build/design something for employees first.
One thing I've considered, what if there were a site where you could rep trusted people anonymously? Then employers (or buyers etc) can see if there's some path from themselves to the candidate, at least to know they aren't some total rando who could be a scammer. The thing is, it's hard to obfuscate the reps if you're answering those queries, and it all falls apart once someone can prove that they gave or received rep.