help figuring HP washing math numbers and cost.

i'll make this short, a nutjob i know says he's gonna aim for max hp, so i'm doing some basic calculations, and i need someone to go over them to make sure i didn't mess up anywhere. we are assumming 500 int from level 100 to 150, all AP's added to MP in this range
class is warrior, so -4 mp + 20 (24 with skill) hp per reset.

500 int means 50 mp each ap, a total of 250 mp per ap.
4 of that mp goes to str, so it's 46 mp that goes towards hp, but that comes later, basically 46 mp per ap.

so every level, you'd gain 46*5 = 230 mp considering it's 50 levels...
50*230 = 11500 mp for washing total after those 50 levels

11500 mp /4 = 2875 resets
2875resets = 57500 (69000) hp from washing alone

is that correct?
and now the reason why i call him a nutjob, the cost:
50MP has to be reset, so 250 mp reset per level, so 12500 MP to be reset from adding ap.
the 500 int every level gave a total of 50 int per level, so 2500 MP that is reset to HP from leveling

12500+2500=15000 MP to be reset, each reset takes away 4 mp, so
15000/4= 3750 resets that one has to buy.

is the above correct? and yes, i know, this is the most stupid waste of money ever, i've said it enough.