Ash, I agree
I have no problem paying for work that's done properly and correctly. You of course got a great deal on (I'm guessing here) the Neuspeed springs at $125. $160 for the install is certainly not unreasonable either. But more springs cost around $200-$250, and two local install shops here wanted in excess of $300 to put the springs in. They, like MBDOC, looked up the hours it took, and charged accordingly. So for $550, I get a set of springs put in, no camber adjustment, heck, from the sounds of their voices, they didn't even sound like they had a clue with what they were doing. One guy recommended we cut the springs!
So instead, I spend $500 for a compressor, $250 for springs, get the luxury of changing them when I want to, adjusting pads at my leisure, AND I can help a friend out who might need the same work done, and charge him for the 30 minutes I work, instead of 3-4 hours.
That's why people do it themselves. Safety isn't an issue when you've got the right tool. And a $500 tool is a minimal expense, knowing some guy isn't going to rip me off for 30 minutes of work, and 3 1/2 hours parking space, just because some book says he's supposed to.