Generally the USD roughly doubles in supply every decade, so the unit value will be halved in the same amount of time assuming no change in overall network value. Since the multiplier in the OP is related to USD, the 6x value still saved in 3 years is with dollars that are approximately 17% less valuable than at the start, meaning the value saved will actually be 5x the value at the start in real terms. I expect Bitcoin to hit $1,000,000 each no later than August 2028, I could be wrong but that's my personal extrapolation. That would be the equivalent value of $830,000 today however, assuming the standard 7% a year USD supply increase. It's difficult to be precise with FIAT values, but this is my best simple take on it.