How much would 2 iphones cost on sprint?

My brother just got an iPhone 4 on sprint and pays $80 per month for it. If i were too go on his plan an get an iPhone 4, how much would i have to pay per month if i was on his plan with him?

Where to repair my iphone 4 screen?

So i shattered my iphone 4 screen yeasterday and I want to get it fixed. I live in Newtown, connecticut and want to find a place near by where I can bring it to get it fixed. I don't want to go to the apple sotre because it costs $100 to get it fixed there. I want to spend less than $100 on it and be able to pick it up later today after i drop it off.
Are there any places like that in my area. Or just a general place where i can bring it to?

How much does an unlocked iPhone 4S 16 GB cost in the US? - 1

I mean the phones that are not locked to a certain carrier so we can use any carrier we want by inserting micro SIM… Also how much do unlocked version of these phones cost in the USA?
iPhone 4 16 GB
iPhone 3GS 8 GB
Samsung Galaxy S3
Samsung Galaxy S2
Sony Xperia S

i want the cost of unlocked version of all these phone models…
is there any website that gives the price details of these phones?

What if I bought an app by accident?

I have an iPhone 4. One day i was looking through some apps and i saw angry birds season. I clicked on it and i didn't notice you had to pay for it. I had no card on my iTunes account, and it installed on my phone. What will happen

My iPhone microphone is not working

A week ago my iPhone 4 microphone stoped to work. It just stoped, did not lose it in the ground or something, just stoped to work. When I call someone or if someone call me, they can't here me, but I can here them. But If I turn on speaker, they hear me normally.
Do you have any thoughts on how I can fix this?