Actually the ultrawide Gsync monitor I've been eyeing is about $1200

Unlike a "gaming" monitor (don't buy the hype), the Rift can only be used for a few tasks (namely, gaming)... the monitor is a general purpose product and will get a lot more mileage out of it for the price. It's an "apples and oranges" thing.

Things like G-sync really are specifically for gaming and they inflate the price significantly. A very high refresh rate is also not useful for most users outside of gaming. In other words, a lot of the value of these monitors really is in features that are only useful in gaming and not general purpose use.

In reality, most of these "features" aren't very noticeable to the average gamer. In the case where it is a noticeable, a little screen tearing really isn't a huge deal (not to mention G-sync requires an Nvidia GPU, which not everyone has nor will have).

Avid gamers do have a habit of going overboard on things, such as buying 64GB+ of RAM even though they never use it (and wont unless they run VM's, or huge services/server software, etc...).

It's easy to spend $2,000-$4,000+ on a super high end gaming rig, but in reality the $1,000 rig will game just fine for a long while before mandating upgrades.

That is a silly comparison that I have seen a few times now.

The monitor will last you for at least five years, the Rift will be outdated within the year.

A non gaming screen with similar specs is around $160. Gamers are willing to pay $540 more just because they want a better gaming experience, that's why $599 is totally ok for a device like the Oculus.