You don’t need a range extender you just need an access point that is fairly cheaper.
There are some slightly more expensive models available that also offer POE (power over Ethernet) so you don’t even have to worry about plugging it into a separate power outlet.
You could also buy an antennae that you can place closer to your room that may help
D-Link Has some nice products HTML Code:
http://www.dlink.co.in/products/Pro-category.aspx?id=4
The cheapest solution would be to reposition your wireless router so you have better coverage to the entire house... Try moving it higher up in elevation and closer to a Door or Window