As with most things – you get what you pay for. Although there are some agencies and freelancers that offer very low retainers for ecommerce SEO, retainers of between $1000 and $10,000 are most common for small to medium-sized ecommerce stores. The exact price should be a reflection of the number of products in your store, your revenue, the size of your site, and how it’s set up. That being said, this is an investment that should more than pay for itself in increased traffic/revenue and faster recovery times when you get hit by updates. My retainers start at $1500, which is also the starting price I offer for one-time projects. This ensures there’s enough time and resources to get you results.