The clock speed (MHz/GHz) is just one of about a dozen factors of which decide the performance of a processor. A Core 2 Solo with a slower clock speed than that 3.4GHz is still going to faster, for example.
What motherboard does the machine have, btw? If it's a decent one you might be able to bump the price up a bit.
What motherboard does the machine have, btw? If it's a decent one you might be able to bump the price up a bit.