[packetslave]

Well, it depends on what your use case for "10g" is. If all you care about is fast file transfers between your PC and your NAS, you can get a small 5-8 port 10gb switch for under $300 that will easily handle line-rate traffic (at least for large packet sizes)

If you want 10g line-rate bandwidth between hundreds or thousands of servers? Yeah, I used to help build those fabrics at Google. It's not cheap or easy.

10g to the internet is more about aggregate bandwidth for a bunch of clients than throughput to any single client. Except for very specialized use cases you're going to have a hard time pushing anywhere close to 10g over the internet with a single client.