From today it is very easy to switch currency on the site. Either from the homepage, in the footer, you can choose between USD and BSV.
You can also choose BSV or USD on the product page.
Please remember that during checkout the price will be automatically changed to USD due to the way that payment carts work.
If you are browsing products in BSV price, after check out in USD, you will bed able choosing BSV payment and complete your purchase in BitcoinSV.