I want to start programing buy i see on net that i need 10.8 osx,what mac laptop i need to buy that is not expensive(under 500e)?
Mac minis are usually the most affordable way, but you did mention laptops. You can always look at refurbished Mac products if you want to save a bit: http://store.apple.com/uk/browse/home/specialdeals/mac
Apple doesn't sell cheap laptops, any one you get can be counted on to be above a certain quality threshold. The cheapest model is the MacBook Air, which starts at $899 new. While it is slower than a MacBook Pro and lacks the Retina display, it's still quite powerful, and is considered a great developer machine by a lot of people. If you want to go the refurb / used route, I'd try to stick with anything newer than 2012, personally. Anything before that probably won't work with the Continuity / Handoff features in iOS 8.