But it's being done in a highly competitive environment, where everything is commodified. Alibaba has commodified manufacturing, shipping was always a commodity, and Amazon has commodified the marketing and fulfilment end.
The problem with commodities is that it's very difficult to create a competitive advantage - if you do happen to find one, it'll be transient and fleeting as others cotton on to it.
I hope the author is also keeping track of the time he spends on this. At $7.64 profit per item, assuming he does sell all 200 handbags, that's $1528 in profit. If he's spent 152 hours on this, that's just $10/hour for his effort. If he ends up spending 211 hours, he's earning less than the US minimum wage.