There are too many variables to say what you should be spending...and even that could change throughout the life of your restaurant depending on what your needs are at any time.
Steve and I had a long discussion about this in the chat room last night.
I believe that a good way to look at it is:
Instead of looking at how many $$ it takes to manage your restaurant, think of more in terms of hours. For example, if you spend a $2,000.00 per week in hourly salaries, how many management hours does it take to manage those hours. In my opinion, even the owner's hours should be included in this figure.
What those hours cost you each pay period will vary, depending on who you have in what position. Susie Q. Manager might make more dollars than Robert D. Supervisor, but the hours should relatively be the same.
The one thing I tell all people asking questions about what is the right percentage for, ie payroll or food costs is, "what is right for your restaurant." Do you think every McDonalds runs the same payroll as the next unit? Do you think Wendys has the same food costs in every unit? Of course not...you have to figure each operation's unique structure of expenses.
Another way you might look at it for an independent restaurant is to label every payroll hour as "mandatory hours" and "discretionary hours." Mandatory would be what you must have to open the doors and operate, and of course discretionary hours woulbe what you spend above that amount.
Also remember, the use of payroll is like using deodorant....more doesn't make you smell better, but to little stinks. It is far easier to build sales than it is to cut payroll.
Howard