Showing both original base price and calculated price (inc. taxes), when using two price fields and rules
I have been thinking of this, but can you delay the setting of the price?

I suppose you are currently overwriting the price when the user is viewing the node? Can't you set the correct price when the product is added to the cart? That would allow you to show both prices next to eachother.

Optionally if you don't want regular users to see the wholesale price, use a module like Field Permissions to prevent certain roles from viewing certain fields.