I recently got fitted for a new set of irons, but as most have said, I'd recommend going to your local pro shop (driving range, club, or public course). For the most part, they will almost always be able to beat the MSRP. If they absolutely won't budge on price, I'd suggest going elsewhere.
As far as the fitting goes, most places will have you get started with the 6i as a healthy middle ground to gauge what you'll need. However, especially for some of the progressive sets like the MP-H4, you will want to hit with some of the scoring irons and longer irons as well. Also, I'd much rather prefer hitting balls on a range than into a simulator to get an idea of how the club feels.
All that being said, personally, I went with the Mizuno MP-H4s. These clubs felt great to me and looked great at address. Also, they give me room to grow into as I get better. I also tried all the current Callaways (hated them all, which was interesting considering I came from a Callaway set), Titleist AP1s, and Ping G20s. The process started out with what I liked and felt comfortable with, got measured for my height and wrist to floor, then got fitted (hit balls outside with a Mizuno Shaft Optimizer) for my optimal shaft and lie angle.