Safe and Cheap Unlock Code for Iphones?

I'm trying to find a website that will unlock my Iphone 4 for a reasonable price, and not scam me. I have been unsuccessful so far. I really don't want to pay more than $5 ( I only paid $2.33 on my last iphone from Ebay), but I can't find anything anymore for less than $30. If there's a reason for this, please let me know. And please also advise if you know a good trustworthy site (not hard on the pockets too!)

Will I have better coverage at school?

So I currently own an iPhone 3GS. I usually never get any AT&T service at school, and if I'm lucky I get 1 bar of service which usually lasts for 5 minutes. I'm getting a Samsung Galaxy S4 over the next few days and I'm hoping that my service would improve. So my question is: If I switch over to a newer phone will I get better coverage or is the problem with my plan?

Unlocking iphone 5s sprint to use verizon?

If I unlock my sprint iPhone 5s will I be able to insert a Verizon sim card and use Verizon services? Also if that did happen would I still be paying sprint or would I now have to pay Verizon. I do not have very good service with sprint that is why I'm asking. I don't want to pay verizons prices so I was just wondering if there was some way I could do this without getting a Verizon contract.

Can a itunes account be shared with a different iphone and ipod account?

I use a different email for my iphone and another for my ipod. If i plug in my ipod into my account that i use for my phone, will it erase my phones information and replace it with my ipods information? If yes, then when i plug my phone into itunes, will it then erase everything from my phone? Since my itunes would now hold my ipods information?

How to import pictures from computer to iphone?

I have a lenovo laptop and i'm trying to import pictures that are saved on it from my old iphone, which was stolen. I have my new iphone plugged into my laptop but i'm not sure how to get my pictures onto it?

Any USA sites that sell cheap iPhones international?

Ok, so I want to buy an iPhone 5 and in my country, they're really expensive and I can't afford one. There are also some sites which have some shops that sell it in a lower price but it's still expensive. I was thinking to buy an iPhone from USA because one dollar is 0.70 euros in my country so it will be cheaper. So is there a USA site that sells phones or iPhones at the best price of the market international?