would the 2.4 be worth the extra money over the 2.1 or 2.2? or would i be better off getting a refurb 2.1 or 2.2 and using the extra cash to upgrade the ram and hd?
Personally, I would spend the money on RAM and HDD space. I just bought the 2.4GHz MBP and the $500 I saved over the 2.5GHz unit bought me 4GB of RAM, a nice case, a .Mac membership, and AppleCare.
I'd take the 2.1, probably. Especially if the 2.2 was $50 or more expensive (with everything else identical between the two). $50 will get you 2GB of RAM (2x1GB sticks to replace the 2x512MB that ship with the base 2.1).