Magento is still free isn't it? And by adding M2EPro your products & inventory can also list on Amazon and eBay's global sites at the same time that they're on your website.
M2EPro is also free up to a certain (quite high) monthly sales volume
While magento 2 CE is indeed free, it's a horrific mess that I wouldn't recommend to anyone let alone someone who needs a store with only 20-100 orders/day.
M2EPro is also free up to a certain (quite high) monthly sales volume