Cost of an agonizer on solarite?

My codex lists the price of the agonizer upgrade as 15 on the solarite, while battlescribe and the few lists I've seen including this upgrade have it listed at 25 points.

I've checked the GW faq and have seen nothing referring to this so my question is... does everyone's codex list it as 15 points?  Are these people just getting their numbers from battlescribe and not bothering to check the codex itself?

I doubt I'd ever take one, I'm mostly just curious if my codex is somehow out of date or inaccurate.

It's 15, presumably because you lose the Shardcarbine.

Thanks for the quick response. The closest I could find was another thread on this board that mentioned "cheap agonizers" on scourges, but it is nice to know my codex is accurate.

It might be good for a backfield harassment unit I suppose, to mop up devastators or similar your blasters or shard carbines didn't finish off. I still think I'd go with the venom blade though.