I am new into this Bitcoin, Ethereum and other cryptocurrency mining. I can see that people in China have farms built just for mining crypto coins such as BTC, ETH, ZCASH, etc.. Here in India, people are selling bitcoin mining rigs for around 2 lakh 50 thousand (approx $3900). If I buy it, or if I build it by my own for some $$ less, is it profitable in India? Or is it better to buy coins from exchanges and keep it for long term so that I can make profits? Any experienced crypto miner please suggest me.