In Business Central now (and previously in NAV) it is possible to define unit-amount (it means price) rounding precision per currency. So rounding is the same for sales proces and purchase prices.

But we have a lot of scenarios (namely, countries!) where we should be able to use different rounding for sales prices (e.g. due to regulatory requirements), usually higher, like 0.01, while keeping purchase prices rounding precision low, like 0.00001 to be able to precisely register costs.

I would be good to have such possibility in Business Central, as such functionality should be created in backbone of the system as it's quite hard to add as extension.