fireworks sales in tents ..

Have a friend that has done the fireworks sales for the past 3 years. They work about 10 days and have to pay out of their profit any employees, but everything else it handled by the fireworks company. They stay on site in their rv for security and being there for the sales. They have made as much as 6 grand clear for the 10 days and as little as $4,500, I guess weather and location does make a difference. I have not heard yet how they did this year as this is the 4th year for them. At the end of the sales time all inventory is picked up along with the sales proceeds and about 30 days later their final check comes once all the items and sales are accounted for.