If iHerb charged you extra customs fees when the package arrived, first look over your order confirmation and the shipping terms.
It is usually up to the customer to pay the customs fees, which are different for each country.
iHerb sometimes has a "Delivered Duty Paid" (DDP) choice. Check to see if you chose that when you checked out.
If not, the fees were probably put in place by customs, and you need to pay them in order to get your package.
To find out more about the price, you can contact iHerb's customer service through their "Contact Us" page.
Many people have shared their issues here and found resolutions. If you have one, feel free to reach out to Xolvie.
Related Complaints
I Report iHerb Order #961266814 Undelivered, Stuck In Customs

I placed an order with iHerb.com in May, specifically Order Shipped #961266814. The tracking information indicates that the delivery was made, yet I have received no package, no notification, and no communication whatsoever. When I try to check the website for more information, I can't find any deta...