Upgrading to the iphone 5 on sprint?

I'm due for an upgrade and would like to get the Iphone 5 but need to know if i will have to change from my current plan to a new one. I always thought that when you upgrade all you do is get the phone and that you have the option to upgrade plans but didn't have to.

Wheres the best place to buy a used iphone?

So my iPod touch broke and I see used iPhones with a cracked back on sale for $100-150, which is cheaper then buying a nee iPod touch. I don't care if the back is cracked because I can just buy a new back for cheap and replace it myself. I'm not going to use this iPhone as my phone, just as my media player to replace my iPod touch. Where's the best place to buy one?

IPhone 5 or 4s, what's better?

Ok so I had an iPhone 4, but it only had 8GB which wasn't enough so I said to my parents I wanted an iphone with 16GB. They got me an iphone 5, which I didn't really want. Should I send it back to get the 4S so I can get like £100 back x

Not recieving text until like an hour later?

I've just got a iPhone 5 on contract from my blackberry, I have switched from Orange to EE & for some reason I'm not recieving certain people's text until like an hour later, mine seem to send straight away it's just recieving.
Any ways to fix this?

Why isn't my sound on my iPhone working?

This has been happening for a couple of weeks, my sound works then stops? Even when the switch on the side is up(not on vinrate) it still dosent work. So when I want to watch videos or music it doesn't work? I've tried rebooting It and it still isn't working! Someone help its annoying me! X

How to find out my iphones last known location?

We have all done some dumb things lately well my mates went one step up and lost his iphone any chance i could find out the last known location i know i can use icloud but the phone is offline could i find out when it was last online and where to help me locate it any help would be great cheers

Iphone 3gs battery draining?

I used to have ios 6.0 on my iPhone 3gs 16gb and everything worked fine but because there was a unthethered jailbreak i decided to go to ios 6.1. Now i'm getting battery drainage on my phone even if i don't use the phone? Yesterday night I let it have a full charge and then the next morning when I woke up the battery was at 89%? What can I do to fix this? I can't revert back to ios6.0 because I don't have the SHSH files so any ideas?

IPhone 5 VS Samsung Galaxy. Which is better?

IPhone 5 or Samsung Galaxy Note II?
Which would you consider better and/or easiest to navigate? Or, any suggestions of a different, high quality phone within the same price range? Any answers would be much appreciated. Thank you.

Added (1). I'm still undecided but thanks for your answers and opinions.