....<snip>....... My price range is around $150, i don't know if i should buy a used one on Craigslist or not .....<snip>......
I wouldn't recommend a used phone of craigslist. Especially if it's your first smartphone.
Do you plan to buy the phone outright and sign up with a discount carrier? Or do you intend to sign a contract?
An outright purchase (sans contract) for $150 will get you a current model entry level smartphone, or it will get you last years mid-range phone on clearance. If this is your plan, I'd get last year's mid-range phone.
A contract phone plus $150 gives you alot of options. You can get just about anything except a newly-released premium phone (eg. the iPhone 5 with 64 gb storage is out of reach, but the iPhone 5 32 gb is within range. Just about any Windows Phone is in range. And almost any Android phone is possible).
If it's your first smartphone, I'd probably go with last year's mid range phone, on a discount carrier, without a contract.
As far as the discount carriers are concerned, remember that:
Virgin Mobile and Solo Mobile are actually Bell.
Koodo is actually Telus.
Fido and Chatr are actually Rogers.
What that means is that you're going to get the same level of coverage, but at a "slightly" lower cost. And they will likely not have the premium phones available (they save them from the parent brand).
Wind Mobile and Mobilicity are the new entrants available here, and they are ALOT less expensive as far as the monthly plans are concerned, but you do have to pay more for the phone up front. They have spotty coverage in parts of the city, and particularly out in the suburbs. So if you live far out in the burbs, you'll be roaming occasionally. Mind you, the roaming rates (for phone calls) on these networks is quite cheap.