The Photobucket message is written in 'half-pidgin' English. Methinks a scam, most certainly.
After reading this post it prompted me to re-read the original photobucket message. The grammer and spelling is spot on. There is nothing "pidgin" about it.
So, then I read the additional stuff that rustyengines posted and it too is perfect.
This, combined with the legitimate/correct email link, indicates it is not a scam and is indeed a legitimate Photobucket email requesting you to spend money with them.
My take on the thing is that Photobucket, a couple of years back and for one reason or another, became money hungry and even now are still after every red cent they can lay their greedy little mits on. You'll get more of these messages, but If you don't want to receive any more of them, then just "unsubscribe". Close your account first though.
Cheers,
Rob