I am going to buy a new imac to replace my 5 year old imac g5. These are the steps I have gone through: 1. 21.5" is big enough for me, so £999 2. But wait, I want a 1tb hard drive as I have lots of music, films and photos. 3. So I need the next model up for £1,250 4. I am now thinking that for just £150 more I could get 27"! £1,400 5. Now if I get 27" then I could get a SDD? £2,000 6. Then I'll want more RAM.. But now I'm spending £2k on a huge screen - doesn't seem right? Can a novice upgrade the hard drive on the entry level imac?