i think Bitcoin is only profitable if done at large scales. you must get expensive mining equipment and of course it consumes a lot of electricity monthly. Also its usually much more cost effective to buy Bitcoins with this money instead of using it to buy mining equipment.
Yes, you have to invest a lot of money to buy equipment to dig up bitcoin to get a lot of profit. But you also need a lot of money to buy bitcoins, and it's a big risk, because the price of bitcoin is not stable, and it's going to go down anytime soon.