In the past we used formulas, but it was getting in the way of how we were changing pricing, so we deleted the forumla, and now we have none.
Although the FRONT-END pricing is still changing. When the plugin is enabled it shows a different price, when it is disabled it shows the correct price...
I personally do use the cents + rounding.
One thing I noticed, if I use the 'quick edit', it seems to not 'change' their either.
I tried to DELETE the formula, but it won't let me delete the formula either, i've changed the formula to an extreme number hoping it wouldn't apply. But it seems...