How much does advertising cost?

[Brandon]

Im starting an advertising service that uses a mix of different advertising techniques, im in the beginning phases of it, I have a very solid plan but I would like to get a rough idea on how much in store advertising costs, or how much I should charge, I obviously will speak to both business lawyer and accountant, but id still like to get an idea so I know what im looking at...ive read somewhere that businesses set aside 10% of profit to advertise, and the businesses im looking to market don't have much advertising aside from word if mouth, business cards and web presence, but I do not want to overcharge, yet not undersell myself, so any advice and help would be greatly appreciated
Thank you