wouldn't this belong into the hardware forum?
The first CPU is actually 2 generations ahead of the 2nd one and a dual core.
The rest of the specs also sound good, licensed xp + office, 3 games, good soundcard.
The only thing which is better in the second comp is the gfx card, but only if the 9800GT is in no working condition.
Can't say anything to the price however, have no clue of the US prices for used hardware.