Sell new one month old laptop hyderabad?

I have a new one month old laptop that I used only twice. I went to sell it back to the shop I brought it from but he is offering only half the price. Does anyone know a good place I can sell my laptop and get a reasonable amount back? My laptop is Lenovo B40-80seriescost me 27,000

1. Flipkart.com
2. Amazon.in
3. Snapdeal.com
4. Jabong.com
5. Myntra.com
6. Localbanya.com
7. Homeshop18
8. Infibeam.com
9. Shopclues.com
10. Firstcry.com

Half price for a used laptop? Sounds like a good deal to me. You might be lucky down the nearest pub, but they would assume its stolen and only offer 25%.