Wow - haven't seen a pci gpu in a looong time.
BUT the question isn't as easy as yes or no - it all depends on what you want to get for what your budget limits are and whether that will meet your needs. What are you looking to spend to get that functionality? If the rest of the setup is appropriate for what you need then pick up a used AGP card for 50-100 bucks and don't sweat it. Depending on brand and model you can definitely get something that can hold its own for a bit . I saw a Sapphire HD3850 AGP go for $55 last week.
I myself have put together a "legacy rig" (as it was deemed on OCN when I asked about AGP cards for the ASUS p4p800edlx). I want to go high-end if I do the new tech so I can do what I did with the Vaio for the last decade and replace bits as they need upgrading; that only works if you start with a bit of head room, so rather than spend $350-400 on low end new and always feel one step behind, I spent it on peak EOL stuff (which will serve the same purpose but keep me from chasing the tech every year with a whole new low end setup. And I can feel like I'm at the TOP of old generation - heheh)
Right now the 1.7Ghz P4 Vaio with 512MB RAM can handle everything I do with it but it can't take the video HD Revolution so I got a spiffy new midtower and some pretty UV lights and then scrounged ebay for the ASUS board, 4GB of OCZ Platinum, 3.2 GHz Northie (and a 3.2 Pressie also), 750 watt PSU and an HIS HD 3850 with IceQ3 and a brand new 640GB WD BLUE Sata HDD from Amazon which should all serve me very well until I can afford to do the next iteration the way I want to even though I likely won't need to.
So, yes, AGP has no future really, but the question is do you need it to have one? I would suggest doing this: Compare what you will get from what you would spend (min and max) on an AGP card to what you would spend (min and max) and what you would get from a new setup and see if the ratio pays off better one way or the other. That will give you a better idea of where the best value is for what you need and want.