Mac's are not as overpriced as people make out, providing you don't buy the RAM from them.
The iMac 27" is a good example of being competitive with cost.
Apple iMac MB952B/A / Intel Core i5 2.66GHz / 4GB / 1TB / 27" / SuperDrive / Mac OS X 10.6 Snow Leopard / Desktop PC
£1500
OK, I can get a 27" for £300 - £500. Being generous, that's £1000 for the i5, RAM, hdd and OSX.
Good deal? *cough*no*cough*