All of my cameras are at least 1080p, but none of them cost more than $150 or so. It's a mix of USG, HikVision, and Anran. Blue Iris costs $40 or $50.
As far as the house goes, I didn't go with a full AV setup. Instead, I have two whole-house WMC DVRs, and Ceton Echos in the various rooms. It keeps me from needing any cable boxes, and makes the TVs super simple for guests. Most of the TVs have Amazon Fire TV Sticks, too. Fancy matrix switchers and distributors are well outside of what I was willing to spend on the project. Among other things, the Fire TV Sticks allow all of the TVs to have access to the 12 main IP camera feed (the mosaic feed is usually on in the kitchen).
I implemented house-wide audio with a couple used Onkyo receivers (TX-NR535 and 636). I made network controlled zone selectors (Arduino + relay board + impedence circuit) that are connected to the receivers to distribute the audio selectively to the rooms of the house (8 zones per receiver). I have integrated it all into my HomeSeer, though, so turning on the zones and setting Spotify or Pandora, and controlling the volume is all done through the normal HA app.