I think that if the Price would be manageable, then I agree!
If level 70s regularly have over 100kk, 5kk For 1 Point sounds like a Decent price!
If you can graduate the price and make it grow exponentially, than that would be great!
You can start at 1kk since not many people would have enough money to buy the resets when needed, then you can update it and tell people about it through Forums or announcement, then the price can be raised as much as it should (let's say first it'd go up to 2kk then 3kk then 5kk later on)
I was under the impression you want 1 standard price, but if you can update it, then I am totally fine with that!
Though it shouldn't work like Reset books, since that can be abused to your advantage.
Once you buy it, you must use it on the spot. You can't carry it around with you to reset later!
Buy and use it from the NPC, like he would be a brown book.
You don't need to grov it manual, you can program it, so it would gow up by every use. Let's say 10% of the curent price (at level 70 would be 1kk) after each use till it hits 5kk.