How much money should I pay an independent contractor to distribute free magazines?

I have a new publication that I want to distribute through regional contractors. The distributor would be responsible for about a 30 mile radius. Distributions sites for the free pub include health clubs, running and bike shops, and rec centers. The pub comes out every 2 months, and I'd like the distributor to check in every 2-3 weeks to maintain inventory at the sites. I don't know what reasonable compensation would be for a model like this. The distributor would need their own vehicle, so I'd need to cover time and gas. Any experience with a model like this?