[member="Kurt Meyer"]
As stated before, if it was truly a repository of all of his knowledge (and not some trick to take over our bodies), then I would say it is priceless. Granted, I would say the same about any ancient holocron that wasn't from a one-trick-pony like Andeddu and the like, but Valkorian/Vitiate's knowledge and power was supposedly second to none, aside from his own shortcomings on the planning side of things.
If you did sell it
You would probably be able to drain much of the OS's funds, assuming they'd have the expected interest in it. Nobody more than someone like the Dark Lord would want this to either destroy it or keep it away from prying eyes to keep someone from rising up against him. I'm sure any corporate elite with experience in the force and any kind of knowledge of "The Emperor" and Valkorian would bid as hard as possible too, so I would honestly be surprised if this didn't reach the hundreds of millions or even billions by the end of the week, if the auction dragged on that long.
If neither you nor Kaile are force users and haven't been able to access the holocron, I don't know that it would be really possible to really gauge the worth of the holocron, and if neither of you are actually able to be effected by it, possibly by being NFUs or some other reason, then there is a good chance that the holocron is just another temporary host to the Sith Lord waiting for some poor sap to open it up and get kicked out of their own body for control - sounds like something he would do, anyway. So there's that risk, too. If the latter-most thought holds true, the holocron probably holds both no value and all the value in the galaxy at the opportunity for some egomaniac Sith Lord to try and use it for power only to get killed/taken over/etc by Valkorian.
Basically, no matter which way it is, you still come out with hundreds of millions upon billions of credits if you auction it.