Any advice on how I should deal with my advertising expense?

[Chris Bennett <..hidden..>]

I would like any advice on how I should deal with my advertising
expense.

We only hand out door flyers for advertising. This works reasonably
well.
The number of hours we spend doing this is determined by how many days
we are not working on any projects.
When there is little work, we spend a lot of time handing out flyers.
When we have a big project or many small ones, we don't hand out any.

I have worked out a good system for estimates, but this item has me
stumped on what to do.

I need to charge an amount on each estimate to cover this cost.
But we do some jobs that may only be $400 up to jobs that may run
$10000.
Also, handing out flyers may generate a call today, in weeks, months,
etc.

If I charge a percentage, I may lose money for this cost.
If I charge a fee, the small jobs may cost too much and lose getting it
and I may not get enough from a larger job.

I had health problems last year, so I don't have a yearly cost to work
with, which might be helpful.

This is a big expense for my company, so I need to get this more or less
right.

Thanks,
Chris Bennett