In the market for new 20 inch iMac. Don't want the 24 inch iMac. 20 inch comes with 2GB RAM standard. Question: Do you recommend paying $100 more for 4GB RAM upgrade? Computer usage: basic internet surfing web based yahoo mail Quicken personal financial software upload photos from digital camera into iPhoto create basic newsletters learn to use Garageband my kids play games at pbskids.com and CD-based games from library Thanks.