L.T.
As far as how much I would pay....I don't know. I've never done it before so I have no idea what price I would be willing to pay. In addition, we are trying to cut back on spending. We are a one income family and my husband's job security is questionable. So at this time, this type of service would not be a consideration for me. Perhaps others feel the same way. If that is the case, you might have a slow start up.
As far as marketing ideas...
What about contacting photographers to see if they will display your info. Maybe you can get some brides or even upcoming high school seniors preparing for their senior photos.
Maybe try contacting local mom's groups about planning a mom's night out sort of thing.
Think of a way you can offer this as a fundraiser. Contact PTA's about it asap (some of them figure out their yearly fundraisers before school begins or at the beginning of the school year).
Many local communities are having summer festivals. Maybe sign on to set up a booth, talk up your business and have a drawing for a free tan.
Maybe team up with a hair salon that doesn't offer this service. You could each distribute coupons to your customers for the other's business.
Perhaps local gyms would post your info. People who are trying to change how they look might be interested in the contouring. Or they may want to reward themselves for reaching a goal.
Is there a friend or family member who can model the finished product for you as you visit with potential clients/partners?
Good luck!