With the boostmonkey, you need to keep in mind that although it is cheaper, it does use the factory solenoid, which will become the bottleneck should you decide to up your boost. If you keep boost around the 15-16psi area, you should be fine. If you decide to get a larger turbo or boost any higher, you'll have issues with spiking as the factory solenoid won't be fast enough.
As for the price of an EBC. . yes it's a lot more expensive. It all depends on what you want to do. If you want to be able to change boost without having to pop the hood, it's the way to go. It's great that you don't mind popping the hood to change your boost, but while you have to make an adjustment, then drive to test it and stop and make further adjustments, I can do it in the car without stopping. Also, I can set one channel for daily driving, yet if I decide I want more performance at a stop light
I can make the adjustment in seconds. Of course, if you want to ask the guy next to you to hold on a few minutes while you pop the hood and get your allen wrench out, that's up to you.