Final Fantasy XI Question

Okay so I came across a "used" copy of Final Fantasy XI: Vana Diel Collection 2008 for PS2 the other day at a local store. I've been thinking of jumping into FFXI and I figured this would be a good jumping off point. I thought there's always a possibility that someone like me bought the game but then decided they didn't want it before using the reg code(far fetched I know but I did that with WOW) and at the worst, I could just return it since obviously they're not supposed to sell this game used. Now before I begin this whole process I had a couple quick questions:

-Is there a way that I can test the provided registration code and make sure it hasn't been used? I currently don't have everything required to play on my PS2 so I figured it would be useful to test before getting involved.

-From what I've read, you can buy another FFXI game for ANY platform and use THAT registration code in it's place. Does it have to be a Vana Diel 2008 version? Do those "sample" discs they sell for like $2 at gamestop work?

-If all else fails, does this have any use to anyone else? I can always just return it but I wanted to know if it had any worth on ebay or something even though it comes without a registration code.

Well it seems like I can use my PS3 to play FFXI so forget the first question, I'll be able to find out for myself. Would still appreciate an answer to the other questions though

No way to test the code sadly.

While it's true the codes have never been platform specific, that "trial" version doesn't get you the free month iirc but most importantly it came out prior to the Wings of the Goddess expansion and therefore does not have a code for that. Prior to the Vana'Diel Collection 2008, it was getting out of hand as you had to enter a code for each part of the game (POL, XI, RotZ, CoP, ToAU, WotG). For this though, they made a single all inclusive code. Hopefully the code works though.

Buy it new.