I haven't broken it down by phone, but I'm paying $190 for an iPhone and four other phones on a family plan. 1400 anytime minutes, nights and weekends not charged, rollover, any calls on AT&T network are not charged to minutes, 200 texts per month and unlimited data on iPhone. One of the things that keeps me with AT&T is that my mom and her sister are both on AT&T and they talk about 1400 minutes by themselves. They live in different towns, so it lets them visit a lot. Both are nearing 80, and it's been quite a blessing for them not to have to measure their minutes.
Anyway, my guess for a single iPhone would be around $80. They bump up for unlimited texts, but 200 does me fine for $5 a month.