Stan Dog.
Just a couple of comments. In the above figures by Billy and Foodbme, You should disregard the sales tax expense. Cart owners, like me, usually round off prices to keep from  dealing with pennies, nickels and dimes. We then have to back out the sales tax to get our actual sales. Almost all B&M operations add on sales tax and the customer pays it. So sales tax is not an expense. Also in Foodbme, payroll tax is not 15% of total sales, it is 15% (varies) of payroll. Foodbme makes a good point in making sure you factor in often overlooked expenses. Most commercial leases are base rent plus triple net. Very important to know if this is the case as it ups your lease payments.
The easiest way to determine your fixed costs ( costs that occur whether you sell 1 hot dog or 500 hot dogs per day)
is to add up all your reoccurring monthly expenses, i.e. rent, utilities, est. payroll, taxes, insurance, advertising, cleaning
 supplies, etc. Take that total and divide by number of days in month, ave. 30, and you will find out how much product you have to sell to break even, (zero net). For example if your total fixed expenses are $6000.00, you must make $200 per day in PROFIT to break even. If your food costs are 30%, you must sell approx. $280 worth of product per day to break even for the month.
So it is very important to know what your actual fixed expenses are as close as possible. Note: These will vary slightly. For example you will spend more in labor to sell 500 dogs a day than 1 dog, doh. That is why you factor in a misc. amount after you think you have covered all these costs.
Also I think paper goods, condiments, etc. should be figured into your product costs and not be considered a fixed expense.
Also start up costs, remodeling, equipment, signage, licenses and permits, etc.  should be figured separately as they are a one time expense.  
I’ve done some business consulting, so the above I feel comfortable commenting on.
Billy and others can better advise you on this next statement I make, but I think you will have to offer more than dogs to bring your daily sales to a desirable level, unless you develop a gourmet line and build a reputation.
 
Of all the above, projected sales is the variable that cannot be pinned down. All other figures can be determined pretty closely.
 
Jerry
Tasty Dogs