Managing vendor price changes

We just migrated to Netsuite, and are having a hard time figuring out how to handle our vendor price changes.

We have several thousand products. The prices are always changing -- generally going up. In our previous system, we kept up with this when we entered the vendor bill. If we changed the "rate" of the product when entering the bill, it would display a dialog: "Do you want to update this vendor price?" We almost always wanted this.

In Netsuite, it seems as if there is no way to manage this. I found the Mass Update called "Update Purchase Prices from Most Recent Purchase", but this seems to use the price entered on the last purchase order, I think. That's not what we want... we would like to update purchase prices from the most recent vendor bill.