How to buy eXRD/XRD
Currently, you can buy/sell XRD only on Bitfinex. But, if you can't use Bitfinex (e.g. if you're in the US), you can still buy eXRD and swap it to XRD.
Note
It's always suggested to buy XRD directly to avoid fees and/or Ethereum gas fees (for swapping and moving tokens)