You may want to look into the Double Everything deal. A one time payment of $4.95 will give you double resources and if you choose to double again, you end up with four times more databases. Here you have the link: http://x10hosting.com/upgrade.php
There's also the options of ad-enhanced accounts. I don't know for certain how many databases you'd get on the ad-enhanced plans though.
There's two options: Corporate, which requires an banner placed so the user does not need to scroll to see it (near the top of page). This option would give the most extra resources. Advanced, which is a text link that can be placed anywhere on the page