Mickeyblues,
IMO, I think some of the doses being thrown around may be a little high. If you're not looking to use the HGH to build muscle, but rather as a preventive anti-aging tool, I think 1 IU/day would be adequate.
However, you don't have to take anybody's word for it. Rather, get bloodwork done, and note your IGF-1 level. Then do what you think is a proper dose for several months, and get bloodwork done again. If you're using it for anti-aging, then you want to be on the high side of the IGF-1 range for a man in his early 30's. By looking at your bloodwork, then you can adjust your dose up or down accordingly.
Not only does 2-4 IU's/day sound high, but even with generic HGH at $2-4/IU, you're talking a significant investment. You may be able to achieve your goals with a smaller $$$ layout while concurrently avoiding some of the sides that some will experience when they go over 2 IU/day.
Good luck.