I m looking for a 4-day-backpacking with low budget,dont feel like traveling to island and South-East Asia.?

Ok I need to ask you something first are you looking to hike in cold weather?? Also are you willing to travel and how far? also it would help if we knew what part of the country you lived in?? then I might be able to help. I have been hiking for several years now so I might be able to help with those answers.

below 20 degrees is not cold weather.... come here in canada and experience -30 degrees for yourself! Anyway, here are my suggestions: Baguio City in the Philippines - experience the Filipino hospitality and see the majestic Rice Terraces, the Elite PMA, or golf at Camp John Hay. Genting Highlands in Malaysia - experience Casino. In both places, the temperature is kinda mild, like as what you specified and both are in main islands. You said SEA on your main question, but said not SEA after - I decline to comment.