I think it depends entirely on where you live, but here in Aus it's definitely cheaper to buy outright (although most fail to realize it). All the phone companies here are obsessed with "Caps" where you pay $50 a month for 2 years for the phone and you get $350 worth of calls, texts etc. The ridiculous thing is call costs are inflated twice that that your added value is, so you end up with about 100 minutes worth of calls and if you end up over you end up over your cap.. your paying ridiculous amounts for calls (end only getting around a 200 mins talk with that cap).

Anyhow long rant aside. I bought the phone outright ($600 instead of ~$1600 on a $69 cap) and am on a data type pay as you go plan... no monthly fees so I usually spend anywhere from $5-25 a month.. with $25 getting me about 1500 minutes talk time and 500 mb of internet quota.

So lets see... average $15 a month for 24 months is $360. So $360 + $600 = $960. Massive saving there. Not to mention I'm going overseas for 3 months and the phone will see no use during that time... $0 a month for nothing instead of $69... love it.