home fileservers?

While business accounts may be fairly easy to get in most locations, they tend to carry a hefty price premium over the residential accounts. In my experience, at an equivalent performance tier, you'll pay 1.5-2x [*] the price for the privilege of being allowed to run services on standard ports.

[*] I have this service at two different locations, with different ISPs -- The first charges 50% more for unblocked service with a dynamic IP. But to get a static IP, you're forced to rent their modem too, bumping it to just shy of double the price of residential service. The second one requires their modem regardless, and it's about 75% more for "business" service with the static IP bringing it up to, again, just shy of double their residential service.