How do you buy Ethereum pow?

As a keen observer of the cryptocurrency market, I'm often curious about the various ways investors acquire popular digital currencies. With Ethereum's rise to prominence, I'm particularly interested in understanding the process of acquiring Ethereum Proof of Work (POW) tokens. Could you elaborate on the steps involved in purchasing Ethereum POW? I'm particularly interested in the exchange platforms that facilitate such transactions, the fees associated with the purchase, and any potential risks or considerations that investors should be aware of. Your insights would be invaluable in helping me navigate this complex yet exciting financial landscape.