So, I am buying a Macbook from a secure Mac site.
I have a pricerange of 0-$400 (or maybe a little over like $430) and I don't know which version should I get.
Apple MacBook 13-inch 2.0GHz Core Duo (Early 2006) - $250
Apple MacBook 13-inch 2.16GHz Core 2 Duo (Mid 2007) - $300
Apple MacBook 13-inch 2.4GHz Core 2 Duo (Early 2008) - $350
Apple MacBook 13-inch 2.4GHz Core 2 Duo (Early 2008) - $400
Apple MacBook 13-inch 2.13GHz Core 2 Duo (Mid 2009) - $400
I never have bought a Mac in my life.
I don't know any big differences...And also, if you can find another Macbook (I don't care about the size.) from a CERTIFIED seller for 0-$400 (or a little over) please give me the links! 
I have a pricerange of 0-$400 (or maybe a little over like $430) and I don't know which version should I get.
Apple MacBook 13-inch 2.0GHz Core Duo (Early 2006) - $250

Apple MacBook 13-inch 2.16GHz Core 2 Duo (Mid 2007) - $300

Apple MacBook 13-inch 2.4GHz Core 2 Duo (Early 2008) - $350

Apple MacBook 13-inch 2.4GHz Core 2 Duo (Early 2008) - $400

Apple MacBook 13-inch 2.13GHz Core 2 Duo (Mid 2009) - $400

I never have bought a Mac in my life.