I've been selling stuff on Amazon online as a side gig for years. Used to sell on ebay as well but didn't find it to be worth the extra hassle, Amazon FBA is where it's at if you want to move any real volume without having to commit to real work on a day-by-day basis.
It's definitely harder than it was. Margins are nowhere near where they were as everything is up across the board (raw materials, freight/shipping, tariffs), and the proliferation of Chinese sellers on Amazon means any easily re-creatable idea without IP protection (which I don't mess with) is going to be cloned a million times with race to the bottom pricing. I move enough volume that I just pretty much let it ride on auto pilot these days for the credit card points and little bit of profit.
It's definitely harder than it was. Margins are nowhere near where they were as everything is up across the board (raw materials, freight/shipping, tariffs), and the proliferation of Chinese sellers on Amazon means any easily re-creatable idea without IP protection (which I don't mess with) is going to be cloned a million times with race to the bottom pricing. I move enough volume that I just pretty much let it ride on auto pilot these days for the credit card points and little bit of profit.