Marketing agency costs range depending on the service being offered. You should build your marketing budget with the following investments in mind: SEO Cost: From $1,500 to $15,000 per Month PPC Cost: From $750 to $5,000 per Month Email Marketing Cost: From $1,200 to $10,000 per Month Inbound Marketing Cost: $500 to $3,000 per Month It's good to remember that the amount you invest per service will also heavily depend on the credibility and effectiveness of the agency you work with.