>At 2021-03 prices these four cost $1,150.92 a year. Today the same nine cost $1,852.92
Is that number really correct?
It seems remarkably coincidental how close $1,852.92 is to
$1,150.92 * 1.10^5 ($1,853.56)
It's pretty much a match accounting for kibblesworth effects.
Forgive me but where does 1.10^5 come into the equation? What is the significance of this number?
Both figures can be arrived to by taking the monthly total and multiplying it by 12.