With the subsidy that the carrier provides, the actual cost of the phone ends up right around the out-of-contract MSRP price. For example, my previous phone (Motorola Atrix 2) I paid $30 for it last march, but I was locked in to a two-year contract with a $20 charge for data added on. So 20x24=$480 just for the lowest data plan of 300MB (I hardly used data, barely going over 100MB a month, but it was a nice little luxury to be able to check facebook whenever I was bored and didn't have wifi). Mind you that wireless data costs the carriers next to nothing to provide (other than maintaining radio towers etc.). So basically once my two year contract would be done, I would have paid $510 for the Atrix 2. And I got it on managers special, the Atrix 2 was normally $100 at the time I purchased it. I'm glad I dumped that phone, canceled my data plan, and got the MUCH better Nexus 4 (while saving about $200).
So in summary, I'm extremely glad I got the Nexus 4, and if it can last me a year and a half then I won't care if I get diddly squat for it since I only really paid $100 (because I saved $200 by switching from the Atrix and getting rid of my data plan).