You can also disable the faulty GPU and run on the integrated HD3000. You lose the ability to connect an external monitor but... my point is - the 15" 2011 MBP's quad-core i7 runs circles around any Core 2 Duo. No need to
waste spend money on a C2D MBP if there's a much faster one around already - assuming that one is working or can be repaired.
Edit: When did you get an aluminum iMac? I thought you were into the white ones
Well, the price range for a 15" MBP core2duo is lower, than for that for a i7-model from 2011 - and if you go for a used one, you don't know, what you actually buy with the model from 2011.
I have a 15" mid-2012 i7-quad for heavy duty tasks (batch-scan/OCR; video-editing) - but nearly all of my regular tasks can be done on a Core2Duo. The late2008 13" MacBook Unibody is meant for a mission critical home-office job, where I don't dare to have an A1260 suddenly fail.
Unfortunately two 24" white iMacs failed during the last 12 months and need service. They were on duty nearly 24/7 for about 3 years ...
I hope, I'm able to fix them, but if the job needs soldering, replacing bad caps etc. they'll have to wait, until I have more time and finally skills and equipment.
So that cheap late-2008 24" 2,66GHz c2duo iMac (8GB RAM/250GB SSD) is filling the gap as my main workstation in the office. It carries a few DEVONthink databases, that are shared within the network through Bonjour/Safari.
There are still four white iMacs (20"/17") left in service, and I do enjoy working on them.