It depends on country. In the western world Salaries are much higher than in the Far East...
Their average hourly wage was $9.46 in 2000.
$8.00 per hour
8.35p an hour
Average worker in Mississippi in 1962 was .82 cents
The industry's 7,896 production workers earned an average hourly wage of $13.77 in 2000.
The industry's 25,000 production workers earned an average hourly wage of $9.25 in 2000
Much would depend on the type of shop and how highly the worker was regarded, and the scale of responsibilities.
The minimum wage in Texas is 7,25. A person in Texas will make various hourly wages depending on the job.
At OLD NAVY with no experience its $7.00/hr at least in Dallas Texas.
Hourly wage
Production workers' average hourly earnings increased from about $14 in 1990 to $18 in 2000.
There are many different SEO Firms and companies. You could start off by contacting a local company in your area. They will give you a quote based off of an hourly wage or a monthly cost.