The smarter way to do smartphones is to use as little mobile data as possible if you want it to be cheap. I wouldn't go without a smartphone. I considered giving it up but I couldn't. Too many basic luxuries like navigation on the phone and being able to use google maps and google search, as well as having an mp3 player and other things on the phone.
My smartphone could be replaced easily for $150 or so with no contract and screens are $25 on ebay. It runs on ptel pay as you go. Doesn't get much cheaper than that unless you get into low-end phone territory which I don't recommend. I avoid any phone that is stuck on Android 2.3 or lower. It must have a minimum of a dual core processor, 1 gb of ram, and android 4.0. Anything less is too frustrating to use.
Basic luxuries? Navigation? MP3 player? Sorry Kevin, I appreciate you pitching in some solid carrier advice here lately, but you've got a lot of growth yet on the whole subject of mobile phones as the hedonic adaptation treadmill's clearly got you by the short and stubblies.
Even many of the lowliest feature phones these days do just fine with MP3 playback. A dedicated GPS is cheaper if you even "need" one, but it's more valuable to learn how to use a map, learn the layout of your city, and plan ahead. You stick with the right manufacturers and style, many feature phones are designed like tanks and cost a third the price. I'd put a Nokia C3-00 or e61 up against any of your Android handsets any day of the week, and I'd guarantee that I'd still get the same level of "needed" internet access using less data, and have a functional phone several days after you did if we were to lose power and have to run the batteries down. If all someone needs is a basic phone for calling, I know of complete new handsets cheaper than what your screen replacements cost that'll last for a good number of years with a little basic care.
Smartphones are designed to wring your attention and your money. You may be going about spending money for smartphone service in a frugal fashion, but take it from a guy who's deliberately scaled back and revised his "it's worth spending a little extra for a Swiss Army Knife due to the extra features" stance. Nobody
needs a smartphone, let alone a
$150 smartphone. Any OS that's designed so poorly as to make a more expensive and "powerful" phone a necessity to keep it
usable is clearly a terrible platform. (Not that I entirely agree with that conclusion and statement, as I've found Android handsets with a quarter of your barrel-bottom specs perfectly usable when there's no carrier bloatware.)
Also to the OP, your iphones take micro sim so make sure you get the right size sim cards when you order them.
There's a
SIM cutter exchange thread. Also, if you have sharp scissors, an emory board and a steady hand, cutting one down on your own from a template 'aint no thing unless you're dealing with the 4FF nano-SIM in the iPhone 5, which gets a little trickier and less forgiving.
Phones are not very frugal and certainly not smartphones with spendy dataplans. Most people these days don't ask if they really need a phone, then just have one. Who has tried going without a phone? What happened?
If you've ever read my superguide posted here (linked in my sigline), you'll note hidden between the lines is my sinister undertone of helping most people realize that they either don't need a lot of this stuff at all, or need so little of it, that there's no sense in spending more than a few shekels on it per month, and ultimately getting their entire communications budget down below the price point that they were just spending on cellphones frequently.
The problem, though, is hedonic adaptation. Take Kevin's cell phone advice here for example. Most people get so used to the idea, you have to ween them off it, and the first step is to re-introduce the concept of "these are just tools". Baby steps, my friend.
Normally, I suggest scaling back and ditching smartphones if the opportunity suits and the user can bring themselves to do it, let some other sucker take it over... but many times it's cheaper and easier to just tell someone to turn off the 3G data and stick with what they have, too. It removes a barrier to switching to the cheaper plan, especially if they find the posted information a bit overwhelming, which is understandable. The 12,000 words or so does make for an incredibly dense, information rich tome to digest.