[TheThinkTank] Dollar value of Volunteer time at Bike Valet or in general?

We're wrapping up much of our summer programming here in Longmont, CO and I'm trying to determine the "dollar value" of our services.

Currently we don't pay our volunteers to do bike parking and we don't charge events for this service either. We struggled to fill many of our bike parking shifts this summer, so, our board will be discussing developing a charge for bike parking and rental of our rack/bike valet in a box program.

In order to do so I'm wondering - dear Think Tank members....

What is the per hour value of volunteer time for bike valet/parking at events (or in general) in your area?

thx.