You are assuming the 2-4K is in US Dollars. Is it, or is it INR? Afterall, the question was about his PSU budget, not the budget for an entirely new build.
You don't want to get a cheap PSU. If none of the ones on Proximon's list are available to you, my quick and dirty rules are: Full range active PFC (no little voltage switch) and some level of 80+ certification. 80Plus tests at an unrealistically low temperature, but they do run them up to full labeled power for over half an hour, and a cheap PSU will blow chunks if you do that to it.
I think it's in Philippine pesos.
For a system
using a single GeForce GTX 560
graphics card NVIDIA specifies a minimum of a 450 Watt or greater power supply that has a combined +12 Volt continuous current rating of 24 Amps or greater
and that has at least two 6-pin PCI Express supplementary power connectors
What power supply brands and models do you have available to you?