Unless the card is a short print, it won't be near $300. WD1 autos were not shorted the way the VD, BBT, Fringe, and Smallville ones were shorted. It's true that Reedus and Bernthal signed less autos than Carl and the others, but not that much less. If they treat WD2 the same as WD1 in terms of production, you will find Rick autos within a week of release for $100.
Also, Reedus was $40-$50 upon release. Yes he had two but it took a lot of time for that auto to jump that high.
Some people have short memories.