If you're not looking for eye candy, AH runs on a very respectable machine.
Overall prices aren't so bad lately, but I would say, in my own opinion, a good baseline for general computing (on a budget) should be something along the lines of:
CPU: Intel dual (or more) core: 2.8GHz or more
Video: Nvidia 9800 or more recent; AMD 5770 or more recent
Storage: DIRT CHEAP! You can get a 1TB drive for $60. GET IT. Don't "only" get 500mb because you think that's all you need. You don't save any real money by getting a smaller hard drive. The lower end for most capable drives is pretty close. If you pay the same price but get 4x the storage, and the drives are both reputable, get the bigger one!
RAM: If you're still on XP or older systems/hardware, 2GB will do. If you're on Win7 or plan on using x64 bit, 4GB or 6GB depending if you have double channel or triple channel mode.
Others: DVD burners are cheap. Combo drives are the norm now, but in 2000 this was rare. You can get one for $20. It's useful. Power supplies in the 600+ range are generally needed nowadays, especially if you plan to upgrade along the ways with better vid cards, etc.
A very basic guide, but at least it's a starting point, no?