Buying btc for selling in higher price and also i am buying bitcoin for transfer money, because bitcoin fee is very cheap. You can compare with other payment method.
It is more ideal if we buy bitcoin and sell it high, but if you are just buying for the purpose of transferring the amount, I think that is too expensive because a certain exchange site would always exchange your bitcoin on a lower value for fiat, that would be fine for you if you have earned it but if not that is a lot of fee.
Yes if you are earning it and then using it for money transfers then its well and good as you are not investing any capital in buying it but buying only for money transfers doesn't make any sense.