Subscribe to SignCraft, you get a free pricing guide with it.
That would be for starters.
Estimate or GraphicsCalc (or whatever it's called. the guy is a member here) are good options too.
But I do not charge by the square foot, I haven't for ages.
I know how much money I have myself in materials for every job.
I know what it costs to keep the lights on.
I used to use materials
X three or four, I even still do that when really in a bind.
But what I am really selling is advertising.
A client will pay $600/month for a tiny Yellow Pages ad but balk at spending $600 on a van which advertises 24/7 for him for as long as he has it.
A client will come to me after seeing my work because he likes my style, even though I am not the cheapest shop in town.
Doing
signs and banners is a completely different type of business than making copies. You would be better off studying about it thoroughly before jumping in with both feet.
If you give it away, you will go broke, and probably hurt the pricing structure of other shops in your area. There is more to it than just pushing a few buttons and charging $7/sq. ft. (which I was charging for banners in 1995)
Even a simple knock-out layout in one color takes design skill to make it effective.
I didn't learn that overnight even if it only takes me 10 minutes to do a mock up.
As well as pricing guides you should also buy some of Dan Antonelli's logo books and the Mike Stevens Mastering Layout book for starters.
Love....Jill