iPhones are mainly more expensive than other phones because of the $30 per month data plan.
Here are a few simple bullet points that might help:
iPhone
* AT&T sells the phone, but doesn't handle hardware problems - they refer you to the nearest Apple Store
* Apple Stores are VERY easy to deal with if you have a hardware problem with your iPhone
* Get a good case and a screen protector to prevent scratching (the housing is plastic, but the touch-screen is actual glass)
* iPhone requires iTunes to backup your contacts, apps, ringtones, pics, etc., or to add music or ringtones to the phone. Can't be done without iTunes
* There is a HUGE selection of free apps in the App store. There are plenty that cost, but there are enough really useful free ones to suite most of your needs.
Data Plan
* iPhone data plan ($30 a month for each iPhone) is mandatory for all iPhones
* iPhone data plan is per iPhone - not shared; each iPhone must pay the $30
* iPhone data plan includes unlimited web access, unlimited access to maps, GPS, the App Store, email, and other online applications
* iPhone data plan does not cover MMS text messaging, picture messaging, or video messaging; these are covered by texting add-ons and are not an iPhone-specific feature
Minute plans
* Minute plans are not an iPhone-specific feature; an iPhone can use any standard AT&T minute plan
* Minute plans start at $40 (450 anytime, 5000 night/weekend, unlimited mobile-to-mobile), and go up from there
* Minutes can be shared among multiple lines, both iPhone and non-iPhone - your whole family doesn't have to have iPhones to share minutes on a family plan
* All AT&T anytime minutes are rollover minutes - don't use them, you won't lose them (for a year)
* Unlimited "calling circle" feature (called A-List) is only available with minute plans of $60 or higher
MMS Text/Picture/Video messaging
* Texting is not an iPhone-specific feature; an iPhone can use any standard AT&T texting add-on
* Texting is not covered by the iPhone data plan
* Texting add-ons are $5 for 250 per month, $15 for 1500, $20 for unlimited
* Texting add-ons are per line, not shared