Should I buy an iPhone 4 from ebay?

I used to have an iPhone 4 but it got stolen back in october. I hate the phone i have now (pantech ease) i went to the att store and they told me i'm eligible for an upgrade in june… Ugh. I'm getting sick of waiting. I don't want to spend too much on a phone. I was considering buying an iphone 4 from ebay with a lifeproof case for 250$. Good deal? Trust it? How can i get an iphone that isn't crazy expensive w/o contract?

Change the design on lock screen on my iPhone?

I've seen on someone's iPhone before that when it's on the lock screen the font is all different? And the sliding bit where you unlock it is different too? Is it in the settings or an app because I really want to change mine but don't know how? I have the iPhone 4S if it helps?

IPhone 4 home button is stuck -any suggestions?

I have an iPhone 4 and the home button is kind of stuck. It works, but only if your press down super hard. It also doesn't make a clicking noise. Are there any suggestions on what I can do to fix it?

How to multitask with YouTube playing on iPhone 4S?

I've tried looking on websites which say to play something on YouTube, press home button twice, slide the screen but across and press play and it should play what you were listening to on YouTube but when I do that it either plays the music on my phone or will not play anything at all, please help!

Does the iPhone 'App Workout Free' work?

I've been using this app for the past month or two. My question is, does it work? Https://itunes.apple.com/us/app/daily-ab-workout-free/id388882339?mt=8

I use the free version, I do the 5 minute workout every other day. Will I see improvement? Whenever I do this workout my abs burn a lot. So I feel like it's a painful workout, but at the same time I don't know.
Please help me.

Added (1). Sorry, the name of the app is called 'Ab Workout Free'

Added (2). Sorry, the name of the app is called 'Ab Workout Free'

How to delete 15k emails on iphone at once?

I know that I can chose Edit in my inbox and select multiple emails to delete, but I have over 15, 000 emails and i'm trying to create more space. Help.

Added (1). How do i set it as a memory device… I wnt to try that first

How to save data on my iPhone?

I downloaded Facebook, Instagram, Twitter and Tumblr.
Do these apps use a lot of data? Do I have to turn off the notifications?
Help please, I don't know anything about "data"