To the OP, you seem overly concerned about having the best headphones bar none, but those may not be the best ones for you. Echoing what others have said, try out as many higher end headphones as you possibly can before making such a large monetary commitment. You may think you know what you want, but what you actually want may surprise even you. As an analogy to headphones, I recently was in the market for a new acoustic guitar. I thought I wanted a Taylor 414ce, which costs $2200, but I made sure to go to a guitar store to try out as many high-end guitars they had before making a purchase. Long story short, the guitar that sounded the best to me in the entire high-end acoustic guitar room was a relatively modest Taylor 214CE Deluxe, which costs $1200 and is not even considered high end, beating out guitars double the price!
Note here that in the audio world, higher price does not necessarily mean better sound quality. People in headphone circles rarely talk about diminishing returns; the reality is that once you get past a certain price range, you have to pay exponentially more for smaller increases in sound quality. For example, my most recent upgrade was from the NAD Viso HP50 ($250) to the Oppo PM-3 ($400). Upon initially comparing the two, I actually preferred the sound of the HP50! It was only after a few weeks, when I had acclimated to the PM-3's sound, that I did another comparison and ultimately decided the PM-3 was the better headphone. Even now, I'd say the HP50 has 95% of the sound quality of the PM-3. Was that last 5% improvement in sound quality worth paying 60% more for? Based purely on sound quality, I'd say no. The reason I kept the Oppo PM-3 was because of what it offers as an overall package over the HP50, not just sound quality. In my opinion, the next significant upgrade in sound quality (for closed, full-size headphones) is the Mr. Speakers Ether C ($1500), which costs over three times as much as the Oppo PM-3! Is paying 275% more for, perhaps if I'm feeling generous, a 10% increase in sound quality worth it? You tell me.