I know that integration of Google Analytics is very easy process and of course it doesn't cost $40.
Apart from this, what do you mean under expression: "Full onsite SEO - 50$"  ?
And why your scheme of getting ecommerce website is more successful than for example, that same ecommerce builder? - http://ecommercebuilders.blogspot.com/  What's the point to pay you if I can use ready ecommerce solution and don't pay you for additional options?