The domain-based license is to use the
website hosting on one domain. You can then sell as many domains through it as you want (you can link it up to an enom reseller account). I'm still really playing about with that side of things but I've just got Paypal to integrate (very easily!) and also Google Checkouts as well with a few minor bits of hassle (it was sorted by the Accountlabs tech support people).
If you buy it, I'll help sort it if you want me to.
It's $45 for the first year and then $15 every year after but that includes tech support and updates.
Just out of interest, how much experience do you have in CSS? There are several included templates but to modify them, you'll basically need to modify the CSS with them (it's not too difficult!)
And if you want to have a look at a customised version, the one I use is at
www.checker-design.com/hosting (it's still just a very small business currently!)