I recently upgraded my raDLS to 4 MB down and 1 MB up. My ISP said its router couldn't handle it. My question is: How much of an investment would it be to just become my own ISP? What equipment would I need, and is it even possible?
It's definitely possible to be your own ISP, but I'm not sure that's what you want. ISPs, by definition, sell their access to other customers. It's a tough business to break into now, and I don't expect many new small ISPs to be successful. With that said, being an ISP doesn't get you free Internet access. Unless you're a huge provider (think Level 3, Sprint, AOL, MSN), you'll need to buy "transit" services from one or more existing ISPs. Even these big providers end up paying each other for access. Transit prices aren't much cheaper than you would pay for equivalent consumer-oriented Internet access bandwidth, so it isn't worth your trouble.
In a nutshell, being an ISP won't get you faster or cheaper Internet access, so your best bet is to get your access...
from a different ISP.