I think many of you are missing the point in comparing the price of zooms against prime lenses. You are only quoting the price of one lens....but the 24-70 is 3 if not 4 prime lenses in one.
You don't HAVE to zoom a zoom lens, but people are lazy.
You like the fixed perspective of a single focal length - then set it on your high quality zoom!
The 24-70 can easily be set and left at 24mm, or 35mm, or 50mm or 70mm. Then you are shooting with a "prime" lens, if not in physicality, in practicality.
I do like the odd prime lens, but those that give me something the workhorse doesn't. Looking at like for like, taking one zoom lens, and we might as well stick with the standard length of 24-70, buy the top quality one (Nikkor 24-70f2.8 = £1200?) and you have, the flexibility and quality of the zoom as we know it. Or, you can view that has having invested in three very good fixed lens lengths.
To compare properly, you would need to add up the cost of all the fixed length lenses the zoom covers. Yes, the added punch of a wider aperture for specialised instances is very nice to have, but working fast, one cannot afford th eluxury of lingering over the decision - too late, the moment is gone. I will get the shot with the 24-70 while you are still trying to fit the subject to the lens on the front of your camera,or you will get what you can and either waste a load of image area (too wide too far away) or you won't get it all in (too long and too close).
Given the luxury of setting shots up, then yes, you can go with a handful of primes, but the weight will be about the same as the fixed aperture zooms covering the same focal lengths.
Take the combination of 24-70 f2.8 and 70-200 f2.8. In those two lenses (you can put one on each body and cover the lot!) you have covered the following classical fixed lengths:
24, 35, 50, 85/90, 105, 135, 180 and 200.
The best answer is to have zooms for everyday work, and cherry pick a couple of fixed lengths for specific reasons. Mine are the 35 f1.4 and the 105 f2DC, oh and the 60mm micro, but that doesn't count because it is for copying and close up work, not everyday eventualities, so we'll ignore it.
Trying to work with fixed lengths all day every day, unless studio based, is very limiting. The beauty of the zooms is their speed of use, you can react to given situation so fast - you can shoot with it set at whatever it happens to be set on, then reframe and shoot again in fractions of a second. If you like the fixed length, then just leave the zoom set on it.
I agree about the finished result of certain lenses, but not all of them. The Zeiss lenses, for instance, give a completely different feel to the result than the Japanese ones.
I have recently bought a 24-70 for weddings though, for the flexibility. But for candids and closeups, and when shooting for pleasure, my 135L will still be king 
