Problem testing computer limits

I finally got Octopus to work so i was dual boxing 2 shamans one on my paid account and the other on a trial account. It worked great and i got really excited to see what more i can do. So i went to create another trial account and a big red box stopped me saying "You have already created the maximum number of trial accounts".

Im not being cheap here... i just wanted to test out how many instances i can run on my computer since 2 was working pretty well. I don't want to pay for more accounts than my hardware can handle. I thought you had an unlimited amount of trial accounts but I guess not. I dont really want to be limited to 2 boxes, and I looked into some private servers but i think Ill pass on that. Would it let me create trial accounts on a different name as long as all my characters logged in are under the same name I wonder?

Just invite yourself from your main account using the "refer a friend" option. Do it 4x. If it ever complains when registering the 4th new char, try from another computer, as Blizzard thinks your IP address is spamming the site.