I need an explaination
 

Can someone tell me how Shopify works. I found a $1000 Duromax generator for $100. I’m not going to go there but I’m suspicious as heck. Free shipping too! Do private accounts sell on this site? I’m confused.

Shopify is a platform that has all the front and backend tools in place to allow anyone to set up an ecommerce store.

They help facilitate the presentation / offering of goods as well as the mechanisms to charge and receive payments.

So yes, it's effectively all private sales.

Shopify will require some PII to try and weed out scammers but it's not possible to catch them all so buyer beware.

I've run into other sites that have incredible fantastic and would have to be fake prices on items. One site had everything imaginable a DIY type guy would want - anything - for $69 with free shipping. Portable tools, power washers - anything.

There is always a new 4000 dollar engine driven welder on Cl for $600. Go figure.

Many years ago I found a plasma cutter on Amazon for something like 25 bucks. At the time some group buys were getting them at $50. I bit down hard but Amazon cut the deal short and banned the seller.

Just don't do it.