That's my complaint with many of the DC hardcovers, particularly the Neal Adams reprints.
I like Marvel's Omnibus versions of several series. I'd already gotten the Masterworks of the Lee/Kirby FF, but I would have preferred the omnibus if I didn't already have them. I think Marvel gives you a lot more for your money than DC does.
In some ways I prefer the Masterworks, because it's 10 issues per volume, and so less bulky to heft around. I worry about the binding coming apart under its own weight on the larger Omnibus volumes.
I've picked up X-MEN Masterworks of 1-5 now, and have "Days of Future Past"(issues 141-142)in another 2-issue trade, so I may not go for vol 6 later. That's the Byrne run, except for issue 143. And I like having them in inexpensive trades that I don't have to worry about. I spent 12 to 13 bucks per volume.
My biggest complaint with the X-Men Masterworks is they have a giant full-page "X" between each story, and I fail to see the point. I'd prefer just a blank page, that doesn't draw attention away from the stories.