I've never actually paid for a sub since the first month I came to EQ on phinny. I've always used krono.
Boxing is all about how you set it up and the classes you run. Two boxing or 3 boxing can be more annoying than 6 or 12 boxing if you have a bad setup. I originally only 3 box'd and my setup at the time was terrible and annoying. I have 6 PC's, with a 6 monitor mount. I already had a lot of experience having to control dozens of pc's and monitors at the same time from working at a missile defense training base for a long time where my workstation alone had 42 monitors on a large U shape desk (18 in front, 18 behind, 6 to the side) and three 90inch mounted TV displays. You'd often have to control this entire workstation solo, at most you'd have 1 other person with you.
Basically how mine is set up is my main character is the bottom center monitor, with the 5 surrounding monitors as my boxes. They are all the same monitor size with very thin monitor frames so all of the screens touch as close as possible, making it look like just 1 giant monitor. I use a pay program, similar to synergy but 100x better, that allows you to control every PC from 1 mouse 1 keyboard instantly. All my boxes only have 2 in-game macro bars full of macros on their screen, everything else minimized. All of my macro's essentially play off my main character, as far as follow/assist/spell combo's etc, which is probably the most annoying part if anything ever happens to my main character or he isn't there, and is something I haven't quite figured out a better way around it. The reason I'm able to do everything so fast and make it appear as if I'm broadcasting by casting spells or doing actions on all 6 of my characters at the same time, is because how fast the program I use is. I basically just rotate my mouse in a counter-clock wise rotation around my monitors, basically like taking your cursor and making a really fast circle. For example when I want all boxes to /target atabishi /pause 3 /follow, I make a really fast circle while pressing the 1 button. For assist and send pets in, /assist atabishi /pause 3 /pet attack, fast circle while pressing 2. For spell combos it's the same thing. I just continuously make fast circles around my monitors while pressing 1 - 2 - 3 - 4 etc.
As far as if I really do decide to do 12, there is a way to do VM's that makes EQ think all of your VM's are individual mac computers. So even if a real GM comes to investigate you, it appears that all your boxes being ran on virtual machines are being played on individual iMac's. There's a button on the "synergy" program I use that will instantly switch all your pc's from it's main window, to the VM window. So you can easily switch between the two groups as if you are only 6 boxing.