Hmmm... Did this too for a dap...... Back while attending college.
I was in NJ then tho...
Don't know where you rest at but check your area for laws regarding outside food vendors and the like....
The Carts are about 8 G's for a basic and you can trick them out much as your money can stand.....Don't know how much product cost these days... but just thinking of Sam's and them big Kosher Best's joints, you could get $3 easily. I used to get them Sabretts... and only charged $1 fo'em. Weekends by the park used to get me $600 total. Spent about $125 including sodas. Since I was a student then.... didn't have to report any of it.... but it definitely kept my pockets and stomach full.