Can I proxy the App Store downloads?

At home I have 14 Active Apple devices (iPads, iPhone, Macs, Apple TV). Just got notice from my ISP that I am reach my data cap for the month and thought on how I can reduce it. Between all the App and OS updates it can easily eat away at a 1/5 of my bandwidth (does not include XCode which I tend to update only while at work).

Would it be possible to setup a proxy like server that will fetch the latest OS update and serve it to everyone how request it on my network?

Thanks,

John