brkkab, prices in India and the cost of living there may not make even 4GB not worth it. And for users who don't play top-of-the-line games or run cad-cam applications, 4GB is quite enough for their web browsing, office applications, and playing movies/mp3s, etc.
unnids, the fact that you have 4GB means 64-bit is ideal for you. 32-bit can only see about 3.25GB so .75GB wouldn't even be used in a 32-bit OS. The only reason you might change it is if you have some hardware that you must use and that does not have 64-bit drivers so unless you have a very good reason to NEED 32-bit the answer is NO, do not change to 32-bit.