They're $75 each from autohausaz.com, $84 if you want Febi.
How much do you think you'll save on them at the junkyard?
There's two things that do in flex discs: Time and Miles. Even if you find one with fewer miles it's still going to be 15 year old rubber. Not to mention the damage you're likely to inflict on it getting it out of the car. You may as well get some nice 15 year old tires and intake seals and O-rings and vacuum hose and fuel lines while you're there.
Even if the junkyard were literally going to let you have them for free, it would not be worth your time and effort to pull them and then install them in your car.
Not to mention that the fastening hardware for the flex disc is not supposed to be re-used, so you would have to buy new, and the only place I know for that is the dealer, and it's probably $50 there. (When you buy the kit at autohausaz you get new hardware as well, I believe that's what the dealer sells, too.)
Bottom line: there are places to cut corners and this is simply not one of them.
But if you're bent on that, then look up your car in the EPC, find the correct part number, then look for that part number in other models. Then you know what is shared and what isn't. Because basically you're simply trying to cut that homework corner and asking someone else to do that for you.