I agree - phone companies must intercept your phone calls and your internet traffic and charge extra money when you use it for business. Excellent suggestion, thank you!
Sounds exactly like what you suggest :-)
Note: I don't know about telephony (they do charge more, but I don't know about their SLAs), but it is true for ISPs (I work for one as a programmer).
Now, it is time to validate your home landline phone. Are you really doing no business over it? ;-)
Everything else is just the way they create price discrimination and exploit the customers' perception of value, much the same way that Microsoft have sixty-three jillion versions of Windows.