these days VR is suited mostly for games and for specialized applications in the industry.
If your wife is interested in games, then the Sony PlayStation VR is the cheapest alternative.
For other applications, maybe the Microsoft compatible headsets may be the best option, but pay attention: these require a relatively powerful PC (the other available headsets like HTC Vive and Oculus Rift have even higher requirements).
as an example: my development PC does not have the requirements for the Microsoft VR devices. It is not a bad machine (a Core i7 series 4000 3 Ghz notebook), but the integrated Intel graphics is not good enough.....