Well how about this, I spec'd out a Dell "ultimite gamer" box. The one that comes with the 9800 non-pro ati card. I tried to aproximate as much as possible the software and hardware options to get close to a Mac as I could... the result was this:
Pentium® 4 Processor at 3.2GHz with 800MHz front side bus,
512MB Dual Channel DDR SDRAM at 400MHz (2x256M)
Dell® Enhanced Multimedia Keyboard Video Ready w/o Monitor
New 128MB DDR ATI RADEON? 9800 Graphics Card with TV-Out and DVI 200GB
Ultra ATA Hard Drive (7200 RPM) with DataBurst Cache 3.5 in Floppy Drive, Microsoft® Windows® XP Home Edition
Logitech® Optical USB Mouse
New Dell Gigabit Ethernet
56K PCI Data/Fax Modem
New 4x DVD+RW/+R Drive w/CD-RW including Roxio's Easy CD Creator®
Sound Blaster Audigy 2? sound card with DVD Audio
No Speaker Option N [313-4514]
WordPerfect Productivity Pack
Dell SecurityCenter by McAfee, 90-day introductory offer
Dell Jukebox powered by MUSICMATCH
Dell Picture Studio, Image Expert Standard
Limited Warranty, Services and Support Options: SAVE $50
XPS Specialized Support Included
No ISP requested
RealOne? Player, with 14 day SuperPass trial
Find a high speed Internet service provider in your area
Save $100 with mail-in rebate. Price shown before rebate. (ya right... could be)
Surge Protectors - Protect Your Investment: Belkin SurgeMaster Gold - 10 Outlet with Coax (for Broadband) (could not unpick it)
That total came out to a 2,917 dollar computer. You still get the slower bus speed, and the 33 mhz PCI setup vs the 133 Mac one and the slower memory not to mention the lack of SATA and a couple other goodies, but you do get a extra 40 gigs then then the mac in harddrive space. It's proccessor is still a bit slower, but you can argue they are close to the same performance. Plus most of the multimedia stuff is already built into OS X and OS X doesn't require a virus scanner like windows does. (could need one in the future, but not now).
So the dell is ahead by $182 (with rebate). Since I personally think that OS X is a better OS then XP and the majority of people who would by a Mac like this one actually use it, instead of just play games on it then I think this is a good trade-off.
(I also spec'd a dell high-end desktop and that came out to 2,547 or so. Now this was with the generic g4 mx 64 Meg vid card, so that is a bigger difference, but then again the ATI 9600 PRO that comes with the 3000 dollar mac is twice the card the gforce4 mx is.)
And if you realy want it you can get the top of the line 9800 PRO card for a extra 300 bucks, but I don't think that is realy a big deal. So then that raises the price difference to $485 with mail in rebate. Which is a pretty big sum, I think that you would probably get a better performance boost by investing in more memory for the tasks that the majority of Mac users do.
When you considure the numerous advantages that the G5 platform has over the current x86 offerings not only in the 64 bit cpu, but in the design of the motherboard itself and the quality of the hardware that Apple has choosen to put into the new powerMac's. I think you maybe putting quite a bit larger emphasis in the slight deficit of video card 3-d power then is warranted.