I don't get you. Based on what I understood you're planning to borrow fiat once you've got enough bitcoin. Does this mean you're planning to borrow money placing bitcoin as the collateral. For borrowed money you need to pay regular interest.
Maybe this can turn to be effective, if the borrowed money is invested on something that brings you regular income.
Yes, if I need something, I would borrow the money instead of selling the Bitcoin to purchase it. Michael Saylor talks about this. If I have to pay 5% interest, but Bitcoin’s price raises over 5% a year, then I would be making money. If I sell the Bitcoin for fiat, then inflation will eat up that money. This is apparently what everyone from Elon Musk to Donald Trump does. They don’t actually have any money. They just have property, and borrow against the property because the property is more valuable than the cash.