your dream is just a dream, i prefer work hard now to get 21 btc from 0.1 btc.
The OP has already worked hard to get the fiat needed to buy 21 BTC.
It doesn't matter whether you earn BTC, or earn fiat and convert it to BTC.
Everyone's dream is their dream and hard work will be required. It's clear the OP has initiated hard work to arrive at the $6-7,000 needed to get 21 BTC into his/her wallet.