Verizon Wireless: Can i switch phones?

[PiNKKK_05]

I have a samsung glyde and i'm on verizon wireless and its been over a year in my 2yr contract, my contract is going to be over in may. i want to get a new phone because my glyde is really messed up and broken and i dont know why. i dont want to pay to fix it but i cant afford to buy a new phone and i dont want to mess up the 2yr contract by getting a new phone in the middle of my contract. i still have my old phone that is now deactivated, i asked vzn if i could reactivate the old phone inplace of my broken one and they said i could and that it wouldnt mess up my contract and i could still get a new phone in may for the 'every 2(yrs) new' discount thing. do you think i could buy a phone off of amazon for cheaper and activate that one inplace of the broken one without messing up my contract? wouldn't that just be like activating my old phone except the one off of amazon wouldnt be old looking and ugly?? and do you know if the phones on amazon are "locked"? i dont really know what locked is but thats what amazon called some of the phones. and if they are locked..how do you get it unlocked? please help! thank you.!