yipsl :
I agree with that. I put an X1650 Pro AGP in an old Northwood system to keep it going a bit longer and it died due to my using a cheap power supply out of a barebones (I'd replaced the barebones psu with a better Coolermaster). So, I have a fried motherboard and maybe CPU.
I got about six month's use out of the card, and though the card's under warranty, I won't build another AGP system. About all I can do is trade it in at ATI for a PCIe card. So, I'll wait till they eventually have an X2600 under their trade in program.
Save up money for a new motherboard and, if necessary CPU. I recommend that no one buy a last gasp AGP card unless they're stuck with a Dell or HP until they can afford a new PC.
I think the issue may be more complex. For many, yes, it is probably better to build a new PCIe system. For others it may be more efficient to simplly pop in an upgraded GPU. Each person has to examine available funds and the value-added use gained from any particular upgrade. Steam's surveys provide several interesting facts.
According to Steam's latest survey summary (December 29th, 2007), PCIe 4X/8X/16X comprise roughly 63% of the graphics cards, while AGP 4X/8X is down to about 31%. If these figures are representative of gamers' boxes as a whole, there are still hundreds of thousands of AGP motherboard owners out there that will take notice of the 3850. Another interesting statistic is that 76% of the Steam Survey respondents still use monitors with 4:3 aspect ratios, with 72% using resolutions of 1024x768 or 1280x960 - both well within the capabilities of a 3850 and acceptable for many of the latest games, except perhaps Crysis and for those enthusiasts that seek higher resolutions on widescreen LCDs. For those who choose to upgrade their existing AGP card, it's just a matter of plugging a new gpu in (provided an acceptable power supply is available) - no reloading operating systems, programs, files, having to re-enter product keys, and installing drivers for other system hardware parts, or incurring the additional expenses for a new motherboard, memory, etc. Thus for some, AGP is still a viable option, particularly if funds and time are short, and/or they are trying to extend the useful lifetime of expensive 2 to 3 year old parts.
And it makes no difference what you have now, 6 months or a year from now, your new parts will be worth less than half what you paid for them, and thus a new cycle begins anew. And the X38 or X48 afficionadoes will be chiding those who simply want to "upgrade" their existing P35 and PCIe 1.0 and 1.2 systems. What goes around, comes around. Ultimately, it comes down to your own personal finances, what you can afford, and your own personal philosphy about value, money, and what you are willing to spend to stay close to, or at the "bleeding edge" of technology.