My company buys a lot of Dells, and it continues to amaze me how what the engineers and managers end up getting costs $2000-2700 when you're done configuring it. Plus, our incredible corporate discounts and volume buying power make it so we end up paying more for the machine than you can get yourself on the web. Most of the time, what the individuals configure ends up being close to a MacBook Pro, give or take a few features. I like how Macs are generally configured with everything at the high end, so you don't accidentally buy a suboptimal components or skimp on features that you add later with more cards.
The corporate "standard" desktop (7 models to choose from) and laptop machines (12 models to choose from) can't come anywhere close to the lowest prices you can find out there. Supposedly, we're saving on IT costs by having everyone with similar machines where parts are readily replaceable and interchangeable, but the IT folks are struggling horrifically with the large number of replacement models (PCs change every few weeks) where a single boot image just doesn't work with all the necessary drivers. In my experience, when someone gets a new PC, the IT guy is in their office for about a week fiddling with things to get everything working. Again, I just don't see the long term cost benefit having owned both.