I think in my mind it's the foolish ever decision to buy a volatile asset like Bitcoin on a money which are borrowed from any other bank or guy with a different monthly interest rate. According to Bitcoin chart movement after every bull season Bitcoin price dump alot, so you have a lot of opportunities to buy small small about of Bitcoin at cheap price by hand earn money instead of taking loan and buying fully one Bitcoin.
I know it will worth later, but let suppose if some hack your account or some how you lose your wallet phrases then it will be very tough situation for you because the interest rate will be increased with time and time and you will have no money to payback. So before taking such kind of decision you must need backup plan too to normalize the situation..