Pros Vs Cons Hindi VS Sanskrit?

I have my plate more than enough full at the moment trying to learn Korean and Arabic, but am always looking for the next language to think about.  I know at some point I want to learn at least one Indian language some point after I learn Arabic.  The nice thing about Hindi is that I can learn Urdu at the same time, which uses a modified version of an alphabet I am already familiar with.  But I really love the way Sanskrit sounds and can be written in so many different scripts, it is truly amazing!  I suppose that so can Hindi if you really wanted to, but other than Urdu I haven't seen it be in anything other than Devangari.  I understan that Hindi has more speakrs than Sanskrit and thus would be more useful, but I also wonder that if I learn Sanskrit I would be able to understand Hindi?  It is m understanding that it was a parent to Hindi, although the Hindu texts are in Sanskrit and Pali rather than Hindi?  So basically, if I have misundertsood anything, please let me know and please help me think about this topic.  Which should I lern?