I don't believe we add on space, but I'm sure you can discuss that with Corey.
Although, for the ad-removal (which is $5/month if corporate), you don't just get to remove the ads. You also get priority support, which is just that: whenever you post in the priority suppor tforum, we go there first for your problems. Also, you get transferred to the business server, which has had NEAR 100% uptime so far. (There was once a down time for a few minutes)