Get an old sn-920 < --- Text Bobbited --- > just be patient they pop up occasionally.
whatever you get expect to buy new batteries. you can also add an external outdoor antenna to get a few miles radius range. they are 1 watt in spread spectrum and fall under part 15.247 of the fcc rules.
When we first went with EnGenius that was what we started with. However, when we added more lines we `upgraded' to what they now call `the PRO' version and added an external antenna. On `*good*' days we can actually answer the phone `in town'! (`Town' is only 4.5 miles away `as the crow flies', though. However, we are talking answering right from the very edge that is closest to our place. It also helps that it's pretty flat between there and here *and* there are few obstructions.) Generally though we mainly depend upon the `long distant ability' of ours for just being able to answer the phone whenever one of us has to be out doing something like setting up irrigation and the other has had to run of to do something like pick up the children from school or something similar. The rest of the time it is the ability to be able to have `extensions' that can answer any line just about anywhere we may need them around the house.
We would almost be `lost' without them and the freedom they provide and after only a short time the convienence they provide more than offsets the initial `sticker shock'.
Oh, yeah... These things are built like the proverbial `brick outhouse', too. While I *don't* recommend doing this, I had one, one day, when I was moving some irrigation pipe on a `small' trailer behind my Traxter XL ATV pop out of the `cradle' on the handle bars, I'd either forgotten to or hadn't tightened up the `cradle' enough, hit the ground, get run over by the ATV's rear wheel, and then get run over by the trailer before I noticed. Except for a `few' scratches here and there on the case it worked, and has been working since then, beautifully. (I now have a leather `holster' that I can either `clip' onto my belt or `hang' via a `stretchy' strap that I carry mine in these days. The only thing that uses a `cradle' now is the GPS that fits a factory designed cradle designed just for ATV use that locks it in *extremely* tight and even then I keep a close watch on it. {WAN GRIN!})
If one is expecting to use one of these for more than just a few years and wants real reliability through all sorts of use and abuse they are, IMNSHO, *well worth* the initial outlay. And, like James_Bond_007 said one doesn't have to start off by `going whole hog' to check things out. Pick up a good used earlier model to check things out and as you get more comfortable and find more uses start setting aside for one of the newer models and `go for it'. Oh, and if you are worried about being overheard the only people who'll be able to do so will be, as usual, our `wonderful?' `gummit'.
Just an `Olde Fart's' 2¢ worth. {VB GRIN!}