Well Haswell has many benefits compared to Ivy-bridge. Some examples of that would be the newer, updated motherboards, faster speeds(Haswell averages 10+% faster), less energy consumption and the next-gen Intel CPU's Broadwell are supposed to run on the same 1150 socket, allowing for more room to upgrade while Ivy-Bridge is a dead socket.
So if you're building a new PC then the Z87 is a MUST and it is priced the same as the older z77. There is absolutely no reason to go with a z77 Ivy bridge if you are building a new PC.
In the end, buying Haswell will give you the potential to upgrade to Broadwell (but not guaranteed). Plus more native features in the chipset.
I don’t think there’s any compelling reason to move from an Ivy Bridge or even a Sandy Bridge based system to a Haswell system– there simply isn’t enough performance and feature differential to justify it. On the other hand, if you’re building a new rig from scratch, there’s little point in investing in end-of-life platforms, so going Haswell/Z87 makes sense.
I recently built a new system. I went with the i7-4770K Haswell 3.5GHz on a ASRock Z87 Extreme4. I'm VERY happy with my decision.