So there's a deal on right now that if you buy a PS3 version from PSN, you get comped the same PS4 version. Same for 360 and XB1, I gather, but I know a lot less about that since I don't have an XB1.
BUT, there's a kicker... you can't pre-load the ps4 version if you do this. Because your license doesn't actually activate until midnight PDT, the store doesn't recognize you as owning the ps3 version ahead of time and won't comp you the ps4 version until then. Or so support tells me, anyway.
So if you take this deal, be careful not to run off to your ps4 and pick up that version too without reading carefully, or you'll end up double-billed and having to talk to someone in southeast asia about a refund. Either wait it out and download at midnight, or don't take the deal and just buy the ps4 version.