If you are happy with the grease then its fine. I think I used grease twice for chain. My observation was that each time it was very difficult to clean it afterwards, and the dust gets stick to it too soon.
Prices:
PSO gear oil GL-4 EP140 310/ltr (plastic can).
In GL-4 there is also EP85w-140 but I can not get its price form their online catalog
They also have multi grade gear oil EP 85w-140, EP 80w-90 in GL-5 range but the quoted prices were for drums.
ZIC gear oil 1ltr is of Rs 450 approx. I think its synthetic.
I had 1ltr bottle of Total (white color) but I have forgotten its price as I purchased it more then a year ago. I think it was around 250.