How much does it cost to have an iphone?

A while back I read you first have to buy the phone for a few hundred dollars (which was way out of my budget) and then the monthly service fee was no less than $50.
I have a virgin mobile flip phone and I pay $20 every three months for service. This is what I can afford.

My cousin just told me she got an iphone and she doesn't have two cents to rub together so, I'm wondering what does it cost now to buy and use an iphone?

Varies by contract and plan
Virigin Mobile sells the iPhone now, at $649 for the phone, and plans starting at $35 a month

if you want one from on of the other major wireless companies (AT&T, Spint, Verizon) you are looking at around $200 for the phone, and starting around $80 a month for service.

Depends on your network virgin Mobile has the iphone now but you pay full price for the phone. Main networks you get a subsided price but end up paying full price over the course of two years

Short answer: http://www.virginmobileusa.com/iphone

My long answer: Every company is different. Virgin mobile iPhones are the cheapest and actualy work better than AT&T and sprint. So since the virgin mobile iPhone is pay as you go, you have to buy the phone first
8 gb- $550
16 gb- $650

Just to let you know, 8 gb will be small if you intend to buy apps, music, and video.

Then chose how many minutes you want
The cheapest is $35 a month, you get unlimited texting, web, and 300 talking minutes (which is a very good deal)

If you set it up on the computer to automatically charge your credit card, it will take $5 off each month.

If you do that ^ with the $35 dollars a month plan, it will cost you $360 a year to use your iPhone.

Depens on the provider you go with and the data plan. Sprint has unlimted data while the others you have to choose how much data you think you would use per month

On sprint Iphone start at $99, but if you want one that is not refurb those start at $149

Phones with data plans for one person start at 69.99, plus tax.

But no matter what if you can't pay more than 20, you can't have smart phone, no matter if you go with Sprint or someone else.

The cheapest place to run an unlocked iPhone that I know of would be on the T-Mobile network, where they have a $30 no-contract unlimited data plan.

Another good choice would be Straight Talk, who gives you unlimited everything for $45.

I would check out the various carriers that support the iPhone on http://phonebillcut.com/ and use that tool to find the cheapest plan that meets your needs.