Damn, that IS cheap. I mean sure the upfront cost to get a lot would be crazy but say you spend the next few years selling them at $25/unit which is still cheap for a case, you'd make good bank. Then again at that scale you'd probably be seen as a business so you'd have to charge sales tax and pay income tax so you'd have to sell at like $50 to make profit. I presume these are fairly low tier cases and not the same cases you'd buy from a computer retailer for $100+.
You might also be responsible for the entire container shipping/customs/brokerage etc stuff too. That's a very complex process and also costly.
Could be a good deal for a small computer builder though. It's hard to find even 10 of the same cases from a computer retailer due to stock, so if you want to standardize your builds this would be a way to go.