Based on these figures, small-to-medium-sized businesses should budget around $9,000 to $20,000 for a PPC marketing agency. For those who are tight on budget, it might be beneficial to opt for a monthly minimum of $1,500 and a percentage of the total cost of advertising spend (or around $3 per click). This can help to ensure that the budget is not exceeded and that the campaign is successful. It is also important to consider the cost of the agency’s services, as well as the cost of the ads themselves. The cost of the agency’s services.