You better be careful if you get a package with a crappy transfer limit like 1 GB and one of the people in your house turns out to be a heavier than average user Heck, even with regular users, you effectively only have 333 odd MB each, which is pretty tight if one of you suddenly decides to download a movie which could average at over twice that

EDIT: Also I definitely do not recommend a wireless router for 3+ devices, especially if you're gonna be sharing files amongst yourselves Not to mention the extra security implications and possibilities of people tapping in on your LAN and stealing your bandwidth Even with MAC protection enabled on the wireless router, they could possibly DOS you instead by scanning for your MAC addresses then faking that same address on their own equipment