From technical point of view its like DK2 but with changeable parts, so for example when Razer develops better display, you can just buy that display and install it to your OSVR. Cool, isnt it.
Im going to buy one soon if Oculus dont put haste in their deliveries...
Razer OSVR costs like $299 but remember, its far from being a consumer version, needs quite a lot of tweaking and its just not ready for the masses yet.