Have you considered just refurb'ing/rehab'ing the existing machine?
Whether that's a viable choice depends on why your friend thinks he
needs a new machine. For what he's doing, it doesn't seem he needs all
that much computing power. A thorough system cleaning and decrapifying,
and more RAM might be all that is required.
That was all I did for a client who complained his 7 or so
year old Pentium IV, 40GB HD, 512MB RAM, WXP SP2 was too slow, and he
needed a new one. He used it for business as well as personal. All I
did was decrapify it, up the RAM to 1.5GB, the maximum it would
take, and update it to SP3, etc. It was like a new machine. And that
was two years ago. Since that time, I've added a larger hard drive,
cloning the old 40 gigger as it was failing. It's still going strong.
FWIW, if your friend does decide on a new machine, whether W7 or W8, be
sure to check if his old XP software is compatible.
Stef