If I am correct then 2.5 pounds = $3.79 American dollars. I can build a decent dog for say $0.65; the 12oz soda cost me $0.32; and the bag of chips $0.22 for a total of $1.19. Cost times 3 = $3.57. Gross profit per vend = $2.38 each. 50 sales gross $119 / 100 sales $238.00 / 150 sales $357.00. I would think that a decent location the sales would be somewhere around 50 to 100. Average daily gross would be $178.50. Out of this you deduct any additional cost such as rent, transportation cost, loans, etc.  $890.00 / week isn t bad for a lunch business. But remember is be conservative in your plan. Start at the break even plus for your lower number. Middle number should be making a decent profit. High number is the difference between the low and middle added to the middle.
Business plans should be written to be attainable. You can fudge the numbers a little for the loan but don t get carried away.
If you are selling Sabretts then sell the 4/1 as jumbo and either the 8/1 or 10/1 as your regular dog. Don t sell a cheap dog unless you have to.

Thanks JodyP, good advice. 

I have seen discussions on here about cheap dogs and I fully understand that some posters customers dislike them. Would you not think it might be different over here since there is less of a tradition? I still want to offer the best, but I felt that price would still be a big pull for some customers and I can still make 50-60p gross profit.

Any thoughts?