Anon it sounds like you want you and your group of friends to have CB Radios- it's older tech so you can find lots of it second hand, gives you a range of 2-10+ miles depending on antenna setup, no license, low/no training, and doesn't call much attention. The world is moving away from AA's as a power source (They honestly suck compared to Lithium) but battery packs exist.
If this remains too expensive and/or complicated, Get a hand crank AM/FM/SW radio like the Kaito KA500, and focus on other types of 'just in case' items.