yes EE is powerful. it's currently the cat's pajamas. but when you have well documented performance issues (simple {embeds} causing whole servers to halt? come on) on top of a ridiculous pricing format, i really don't know why people buy into it when there are so many free options available.
basically, if you're looking to offer it to clients, for a commercial license thats a flat $250 right there. if you need the integrated forum on top of that, theres another $100. For upgrades, every year after the first "free" year is another $40 yearly subscription fee unless you don't plan on keeping EE up to date for some reason. Now if you wanted to manage multiple sites, on top of all the aforementioned fees already, you have to pay another $200 for the multiple site manager, and that only gives you 3 'free' sites (which all have to reside on the same server) until you have to pay ANOTHER $50 per site you want to manage.
now obviously thats pocket change if you're pulling in relatively large clients, but still...