Some of them are $500 or more, but there's cheap ones too. One of them, somebody asked if it supported 2560x1440, which is my resolution, and they said it didn't. I wonder if that's really the case. Well, I don't know if my TV supports that anyways.
No idea why they'd cripple it, let it support 4k, but not 1440p.
One of them said something about a gigabit switch, so it might not be limited to 100 Mbps.