I was drawn to the iOS platform since the App Store was announced. I could just see the potential from day zero, after initially dismissing the first generation for its limited functionality pre-App Store (having been used to loading .jar applications on my then-handset).
I had just finished GCSEs and heading into Year 12 in 2008 when the App Store launched, I think. I did a comprehensive price analysis over the lifetime of the contract to find the best option for me - and I've done the same every year when I upgrade to the new model. I was with O2 until switching to Vodafone from the iPhone 5 onwards.
Of course the contract had to be in mum's name, but I paid for the handset (I always went for the highest capacity) and the roughly £50/month contract cost. After 12 months when the new model is out, I recycle the handset with O2/Voda, which almost recoups the initial handset cost. These costs are easily covered by any summer or part-time job.
So basically, I always have the latest and best spec iPhone. The net handset cost to me every year is less than £100 (sometimes £0). Then I pay about £600 in line rental over the 12 months, but this gives me unlimited minutes/texts and generous Internet (used to be 500 MB back in 2008, this year with my 6 I get 20 GB hehe). I think that's perfectly reasonable for a truly life changing product, and one that I use for many hours every day - probably more than anything else in my life.