Err... 7% higher max speed will not increase the lifespan of the computer 3-5 years. It makes more sense to upgrade to the latest base model more often and take a smaller depreciation hit on the resale. On average you'll have a more performant machine at a similar cost or vice versa.
I just got a new job where the CTO actually insists on getting the 2.4 even though I said I'm fine with a 2.0. He would even prefer I get the 15", but a) I want a 13" form factor and b) I can't stand the TB, would much prefer hard function keys and more battery life.
But it makes sense for a company to spend that extra $300. As a software dev I'm a fairly costly widget. This machine will probably last a good 2-3 years before upgrading. There are times when that speed will come into play... when load testing or running automated suites, tasks that can easily take 10+ minutes. If you can shave a few precious minutes off each day over time that adds up. Not only in time but in ways that keep my focus in check. That stuff adds up, but for 97% of the time, the extra power ceiling is not reached or needed. And it certainly won't make the machine last any longer for its intended purpose.
