Hi ,

I have seen many clients of mine having their Personal Website and they also sell on Amazon or Ebay Or Etsy as well.The Only reason is that they want to expand their market reach and More Profits and ultimately what their goal is. So adding new platforms to sell is always profitable what they think. 

I am not sure what everyone else thinks about it but i also believe that if selling on multiple sales channels will somehow increase the Profitability and reach.Hence i might have to price my product at 22$ to compensate the fees associated for selling. But as you know Amazon or eBay are very big Marketplaces and customer hits are more on these rather than personal websites as it may not be that much popular. So there are upsides and downsides.