I think we need to clarify and expand the question to something more accurate and eliminate any build in assumptions.
1) Define the Issue.
>> Curious if you could just buy the headset itself. Not the pro version nor something that isn't a Vive.
- Will a HTC Vive(v1) Headset work standalone with no peripherals?
- Can you purchase a HMD with no peripherals?
Q) Will a HTC Vive(v1) Headset work standalone with no peripherals?
A) An HTC vive can be used without the controllers, but the basestations assist the tracking / roomscale. Now, I believe the headset will turn on, but you will lose your positional tracking. At best, you might get 360 degree headtracking, but it would be like having a Smartphone HMD, so your experience would be INCREDIBLY limited. This would also depend on the Driver version of the Vive.
Personally, I feel like I've run into this scenario when troubleshooting my Vive or a driver issue.. but I've never actually tested to see if I could get the system to work without the Lighhouses.
Q) - Can you purchase a HMD with no peripherals?
A) Yes, pretty sure you can find them on Ebay as used devices. You can not purchase them new, unless you talked directly to HTC for a replacement part order. (so I guess.)
I think the main question anybody would ask in response is "WHY?". It would be like buying a high-end gaming PC, but saying you don't want the graphics card or a mouse.