You can only get 1 jurachi per game.
That is in the way that U get jurachi in your game, then if u want another u gotta start a new game
U can only send jurachi to Pokemon Ruby/Sapphire, i've tried with FR/LG/E an it just dont work... but u can trade jurachi to the other games from R/S.
And as for ebay... I got my Bonus Disc brand new and sealed for 20 bucks.
It's real. Works Great and does everything it's suposed to.
Either look up the seller mrhotlineking
or look up pokemon colosseum bonus disc
He does have more and should be one of the first few auctions in the list (if you look up the item).
It is a "buy it now" auction wich means 1 click an it's your's and he ships really fast. right now he's listed it for 24.99 + Shipping.
That's about all i have to say for my very first post *cough cough*
Hope i helped!