Where do stores buy electronics in bulk?

I'm just wondering where popular stores such as Best Buy, Walmart, and Gamestop buy their electronics in bulk from. Is it possible for a normal US citizen to buy them so they can start their own business or sell them online. Thanks. I'm also talking about iPhones and Macbook Pros (Apple products and samsung products).

How to know if a iPhone 5 doesn't work or just has a dead LCD?

How do I know if a iPhone 5 doesn't work or just has a dead LCD?
A friend of mine gave me an iPhone 5 he had that has a broken screen, he was able to use it since touchscreen was responsive. However last week his phone just did't turn on and he gave it to me as a gift.
Is there a way to know if the phone is totally dead or if the LCD died.
(For example, Android phones vibrate even when the LCD is dead and most have a boot animation which you can hear)
Any ideas, comments etc is appreciated. I don't want to buy an LCD for no reason.
I have never owned an iPhone, but if I recall, the iPhone does not have a boot animation or sound that would confirm that the phone did turn on.

Downgrading iPhone from ios 8 to ios 7?

So i'm buying a iphone and it was upgraded to ios 8 but there's a way i can downgrade it so it doesn't glitch can someone send me a link or tell me how to downgrade thanks. I upgraded my old iphone from 6 to 7 so i kinda know how. If I downgrade my phone will it be normal again

Get iPhone 5s or wait for 6? - 2

This is my first time getting a smart-phone. Should I get 5s now, or wait for 6? It will be a 2 year contract. Carrier: Verizon.

What is the point of a tablet?

I already have a macbook air and an iPhone. I personally don't see the point in getting a tablet (I guess it would be an iPad considering I'm already on the apple bandwagon) and to me it just seems like a bigger phone and a smaller laptop that does basically the same thing.

If i were to for some reason get a tablet down the road, what are the benefits?

*I'm going to be a college student soon if that means anything.