Anyone know any good AND affordable VR sets?

My twin bought me the nicest, most considerate present I think I've ever gotten, and I feel a bit guilty for not getting her a proper present.

I know she used to play some VR games at her old school dormitory, and that she really wants to play again.

I know nothing about VR sets, though... Never tried one, so I have no idea what she would like.

Edit: by affordable, I mean under $800.