A proper stereo setup also has separate left and right channels ;) I don't even sit at the centre of my two DLS M66s, and I can hear the whole stereo soundstage.
I like that this Headphone Edition is also a high-quality pre-amp. Just buy some good amplification and you're ready for "proper" stereo.
About $350, but that was a very good price I gave someone from another forum I manage, and only because I found out that those ACA ports on PS5 and such are perfectly fine for me. According to sold items on eBay, the price differs quite a lot, depending on condition.