There's a lot of unlocking website spam posts both here and on the Koodo community as well. Don't listen to them.
Telus unlock is the cheapest out of the carriers and it includes iPhones which is pretty sweet, but for any Blackberry I always recommend Freemyblackberry.com - free code after 24 hours or $3 USD for an instant code.
For any Android or WP I recommend cellunlocker.net - typically cheaper than any carrier, secure payments through PayPal, and incredibly fast processing time; typically 5 minutes for a code.
iPhones... Try and use your carrier or don't buy them 😛