I thoroughly recommend pretty much staying full time on CPF.. Mac's are rare on the second hand market and get snatched up within 15-30 mins.
Have you checked the Cpfmarketplace?
I like to consider myself quite lucky - I was looking for one and got approached separately about one for sale. Be prepared to pay a bit for one, but if it was beat up I quite understand. Go by Mac's prices as a guideline. They have good resell value and don't really drop. Usually they go up if modified with tritium vials or special custom work after being purchased.
EDIT: I also understand why they don't usually sell - once you get your hands on one you don't want to let it go. I'll be keeping mine til it conks out.
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