Consolidate websites

I have a bunch of websites (7) in IIS that I've transferred into HC7 using the Migrate -> Import Website function. This worked really well - the problem is, I had to import all of them as separate plans and they all need to be domains under one account's plan. Does this make sense? Basically what I want is the 7 sites I imported (which each are on their own plan @ $150/month a pop totalling $1050/month) to really just be domains under a single plan (so that all of these sites together are on one $150/month plan) Is it possible to do this using the interface?