It's funny because I went through this in reverse: I was an eCommerce site owner who got into web development.
This is not meant to sound snide, but I'm really curious: How can you design websites for 2.5 years and not know html? Even using Dreamweaver, it seems like html would have "worn off" on you in that time...
Anyway, if you already have a grasp of web development, I would suggest doing the eCommerce site yourself. You'll learn things fast enough.
I use
osCommerce for eCommerce sites. It's an opensource shopping cart and once you get the hang of it, you'll never use anything else. Great support community and scripts available to make it do whatever you want.
The bad news is that osCommerce takes some learning and patience. You'll have to learn at least a little html, php, and mySQL. The money you'll save doing this yourself instead of outsourcing it will be tremendous. Not to mention the fact that you will be able to use these skills in your web design projects.