In Spain, at least, there are taxes that must be deducted (the interprise must make this payment for you to the tax office directly). These are called IRPF. But at the same time we all must pay IVA (I think you know it as VAT). This ammount (%) must be added to the price of the product. (and also payed by the company to the tax office). So, when we say "aplicar los impuestos vigentes", that means we must apply the taxes (increasing the product, but also duducting). How would you say it?
Nundah, I think you're complicating it unnecessarily. The buyer is just interested in the final price, they don't necessarily care how much of that the seller has to pay to the tax office. And your original just says "aplicarle los impuestos vigentes".