I agree with pretty much everything above. Man, my switch cost over $900 (but that was only because it was VoIP ready for hosted VoIP). Don't want to get into that VoIP vs VoIP talked about on here. I could be wrong anyway. But, it is a managed switch, though I have "managed" it about three times in two years, lol. For the most part, switches are probably the one part of the network that is set it and forget it.
I keep thinking wireless is going to catch up and surpass wired either by sheer technology or by the fact that no one really wants to rewire every time. I have no idea if I would want to rewire to 10GBS if it came out. Of course, fiber networks will probably be next.
My guess, without using tools like netcps, etc. transferring actual Mbs of files such as a 500MB file over a 100 vs 1000 MB cconnection would be much faster. But, I doubt accessing a file from a database would be especially with SQL.