I had a friend who worked for 75 Ark and he said there are tons with the WTC cover officially pressed up. Supposedly the label is just sitting on them and they're in their main offices in NYC or something.
I think it's gotten alot more common lately. I haven't seen Ebay prices but here in the bay you can get them for around $25.
Also FYI the only thing different is the front insert. It's not even a complete booklet - just a 2 sided front insert that shows the cover.
KM