Is this fixable? And if it is can I use it while keeping my current contract?

I have an iPhone 4th gen and I was wondering If I could switch to my brothers old iPhone 5s. I'm not sure if it's fixable though. The home button fell off and the screen is in horrible condition. A rough estimate of how much it would cost would be great too.Is this fixable And if it is can I use it while keeping my current contract - 1

If it still works… You would have to find a repair shop or someone who legitimately fixes phones for the price. & You can switch. You would just have to talk to your carrier about switching your phones.

The screen about $60-80 but let me tell you this… BUY THE SCREEN YOURSELF because they charge you for the screen so it's better if you buy it then it will be about $30, but about the home button hmm I'm not even sure if that's fixable.

Also you can add a home button in the screen you know what I'm talking about, check if it still turns on