If you are willing to spend 21k, why not get Nikon D3000 SLR, which is slightly more than P510 but, you get a SLR! Just saying.
Edit:
Aperture is one thing because of which I suggested you to go with HS25 EXR and it's a little cheaper as well.
Otherwise, Nikon 510 is better in almost every aspect.
I agree the 0.2 f-stops might not be that much of a difference, but it's saving you a little money.
Go to a store, Croma or something and check the two cameras, then decide.