Is this a deal?

I see wallmart has a deal on a laptop. It is a hp ze2308 AMD sempron
2800+ processer, 1.6 GHz 256MB ram 40 gig HD built in wireless for $378.00. Is it worth buying? Also will I be able to upgrade it to 512 mb if not I dont want it. I have a compaq presario 2100 that has a bad mother board with 2 256 mb ram chips. Will these fit in the new hp? Any answers to these questions will be great.