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If I have to pay 5% interest, but Bitcoin’s price raises over 5% a year, then I would be making money.
You're not really gaining anything unless you sell them right? You will just be paying interest regardless of the fiat value of your BTC. What would you do when you borrowed money and then BTC price drops?
It's easy to say things when you have not been into those situations yet. Focus on accumulating those bitcoins first before saying what you're going to do with them.