Regarding legitimacy, I'll leave that to others who own such things. My gut instinct says yes but I am no expert in shrinkwrapped orange B3s.
However, I have no idea what you paid for it, but if I paid any more than $200 for something and it was shipped in a envelope like that, I'd be straight onto eBay and my credit card looking for a full refund. Whoever packed that is a dick.

Two quick comments:

-- It's very, very common for orange B3s to exhibit warping from too-tight shrinkwrap

-- If it was faked / post-production shrinkwrap, they probably wouldn't have bothered to include the tears or strip of scotch tape

Without better pictures to be sure, it looks legit to me.  However, it's pretty criminal to pack a $7600 item in an envelope like that, which also doesn't bode well for its authenticity (a scammer isn't going to pack a fake well, he's going to toss it in an envelope to you and disappear).  Once you reach this kind of price point, unfortunately, the motive (and profit potential) is definitely there to try and create a professional forgery.

Foul

Stratochamp would point out that shrinkwrap isn't a condition, so I'd imagine he'd pop it open, treat it well, and press it flat over a long period of time.
I'd probably do the same, because even without the shrink the ROI is gonna be high unless you're forced to sell during a great depression or a world war.

If you ever have to ship it, put it in an envelope, box it up in a big cardboard box, buy that bonded cardboard angle stuff you can buy and reinforce the corners of your box, fill it with foam peanuts and wrap the whole box with seranwrap and then brown paper.

Aside from that, the threat of returning it to the seller, in the same packaging he shipped it to you in, using the same carrier, should be enough to get the seller to refund $600 and make his own claim against the insurance he clearly made you pay for. This is something eBay should deal with, and eBay should also ensure that you're not left out of pocket on shipping and insurance if you do return it.

Is it worth $7600 as a collectable piece? I don't think so. They're not rare. We see them regularly on eBay. And the PDF was published by WoTC for everyone for free.
Is it a good investment? It will beat inflation, and provided you look after it and don't lose it in a house fire, it'll probably return more than if you'd stuck the money into a mutual fund or T-bills over the next decade.

Thank you for everyone's advice. The seller offered a return on the item. I have a hunch it will be on the Ebay market soon.

victorsword wrote in B3 Palace of The Silver Princess-legit?:Thank you for everyone's advice. The seller offered a return on the item. I have a hunch it will be on the Ebay market soon.

As FoulFoot posted above, the warp in the shrinkwrap is not uncommon.

If you can get it for say $1500-$2000, it's not a bad purchase (even in its current condition).

But not $7600....  

Excuse me Deadlord, what was the reason for that ad hominem attack, saying that my ethics are warped?