EDIT: I asked the costumer service of the online Taylor Swift store, and they answered that the online store DID in fact sell some signed Speak Now deluxe booklets.
The seller does have PSA, but I don't solely rely on that.
mine for example and $150 is too much, I got mine for 50
3 Examples
Permalink Reply by Rose on April 28, 2014 at 12:46pm
I've just never seen a signed Speak Now deluxe before.
And I figured: if the official online store would've sold them, then pictures would definitely be floating all over the internet. But there are none...
EDIT: they did sell some through the online store.
Nor PSA nor charging above market value are guarantees that something is real. Unfortunately, you'll never know if something is real, unless the person signed it in front of you :(