Like you I observed the same listing on the PSN store. PSN is offering the PS4 client for free, but it does not actually give you access to the game. For that you have to purchase an account. Yes, the entire process is extremely confusing.

Since I already had a credit on my PSN account, I went ahead and purchased the PS3 version and only ended up spending $10. I checked Mog Station and it does look like it will take in my beta character with no problem. Ill download and register the PS3 version when I get home tonight, and hopefully I will be able to transfer my toon over on Friday.