I need to update my purchase prices and sales prices.

I have figured out how to update the price books for both based on a certain % price increase but I can't figure out how to get the Purchase Price in Item Purchase Data or the Sales Price in Item Sales Data to change to the new price automatically.

How do I do this?

Thanks

As far as I know there is no way to change the purchase and sales price on the item master automatically. The system only calculates the cost price automatically.

You can do this using a customization, no standard baan way as far as I know.