This is not a good example. first the Ticket had no Real world value and second it worked forever. CREDD Is 20$ and so long as it stays 20$ the cost will balance to an equivalent in (lets call it gold cause I'm lazy) Gold be that 20g or 2000000g. Also CREDD is consumable.It goes away. Its like food. If people decided that (X) gold is no longer worth 20$ the free to play players all starve to death. Granted is Vastly more complicated then this.
What you are probably going to see is stuff like in eve popping up. you'll get people like Gyoin using "gold" to buy CREDD and Employing Players for said CREDD to preform tasks to keep him on top of the market on a given server.
Hmm? I thought beanie babies lasted forever and had no real world value. Maybe [url]http://en.wikipedia.org/wiki/Pogs[/url] are a better example?