Matt, I find 'what to charge' the hardest aspect to work out. You've obviously factored everything in (and the project seems comprehensive)to cover yourself and if you're comfortable with the price, then see what they say. I tend to dwell on that too much - for hours sometimes - and there's nothing more annoying than putting a cost to a client and being told, "Gee, that's cheap!".
IME you can always come down but can't go up. I know people can have really cheap SEO articles bought over the net but, honestly, I can't work out how the writers make any money on them. Good luck and I'm interested to know how you go! - Gioff