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.
I think you can actually have both ways to be efficient depending on how you will do it and your background knowledge to both methods. If you prefer to mine and you are good at it, the expenses will really worth it. But most us rather buy bitcoin in its lowest possible price because it is easier. You should just be good at estimating so you can earn here in this business of bitcoin.