Whole House Sound on the Cheap

I happen to like the luxury of "whole house sound". I don't consider myself an audiophile, but it's nice to be able to queue up music on a Saturday morning and be able to move through the house about my business and have it stay in sync. Sonos seems to be the Gold Standard here, but I can't stomach the price. Apple's AirPlay works well with Apple hardware but leaves a bit lacking in terms of multiple speaker controls and receiving sound from a variety of sources.
So, here's my preferred solution:
1. Buy AirPort Express receivers from Craigslist.
There has been three models of AirPort Express receivers. The latest model is nice and all, but for the purpose of sending sound the previous model (A1264) works just fine. I paid $30 for both of mine. Try Craigslist for yours. The older model works fine but it is only 802.11 b/g and probably best left to its own network.
2. Hook cheap speakers/amplifiers to the receivers. Again, Craigslist helps here.
Your own taste for sound quality dictates here. Frankly I'm no audiophile so simple powered speakers and maybe a subwoofer work just fine.
3. AirFoil running on my laptop sends sound from any source
AirFoil is an amazing - cross platform - piece of software that "just works." The app can capture sound from any playing source - browser, Spotify, Pandora, iTunes, etc. - and stream it to any of the receivers on your network. This includes Apple AirPlay devices, other phones running the "speaker" app or other computers running the AirFoil software. The software works well enough to sync sound across my whole house with now pauses or phase delays.
4. AirFoils (very recent) control app lets me adjust sound and speaker zones on the fly from my phone.
The very recently released AirFoil control app now lets me control my laptop sound source from my phone. It also lets me control the individual volumes of all the speaker zones. This is amazing, as it lets me cue up music in Spotity or iTunes and then change things on the fly from my phone, like when I'm chilling on the porch.
I estimate the total cost per "zone" is anywhere from \$30 - \$74.