A number of eBay "sellers" have gotten hold of various Amtrak discount codes and are peddling them on eBay.  Amtrak's discount codes are not for sale by anyone for personal gain, and doing so is considered theft.  Amtrak takes direct and immediate action to get all such sales stopped.  Further, for anyone buying a discount code this way, please be aware that many of them have various qualifications for using them, and agents and conductors may very well ask you for proof that you qualify to use the code.  Think hard before you decide to go into this "business", and think hard before you "buy" a code from anyone - none of them are authorized to do this.