My iphone 4 is on it's way out so what alternatives are out there?
Looking for a budget option due to buying a house etc but not adverse to a second hand handset.
Any recommendations? (Preferably android) 
You can get a brand new unlocked/off-contract Nexus 5 for 300-350. Check first with your carrier if the Nexus 5 is compatible.
Nokia 521 via T-mobile = $70. Windows phone, no contract.
It has GPS, once you upload the map, you don't need internet to use it.
Nexus 5 is a bit expensive and the Nokia 521 is a bit basic...anything in between?
I got a moto x on amazon for 4.95 when my iphone broke and I didn't want to spend 200 bucks on a new one.
If you aren't a phone snob, the moto x is just fine, plus the active display thing is pretty slick.
looks like if you have an upgrade available, a moto x is 0.01 (yes 1 cent, lol) on amazon right now, with a 2-year contract on att and verizon
http://www.amazon.com/Motorola-Moto-Black-16GB-AT/dp/B00EKXGIKE/ref=sr_1_3?ie=UTF8&qid=1406831254&sr=8-3&keywords=moto+x+at
http://www.amazon.com/Motorola-Moto-Black-Verizon-Wireless/dp/B00EP2BYHW/ref=sr_1_1?ie=UTF8&qid=1406831396&sr=8-1&keywords=moto+x+verizon
What's best prepaid plan for the money? I use data for checking emails, facebook, some browsing. Maybe 1.5 gb a month. Live in socal.
Tinerrz - Nexus 5 is a bit expensive and the Nokia 521 is a bit basic...anything in between?
Moto G 4G is 200-220 off contract.