Yes, every time the cart is viewed in the user's browser, it either reads their existing cart cookies (if present) or sets new ones.
However, I just remembered we support a cart customization parameter to determine the cart cookie duration, which accepts a setting of 0 days to not set a persistent cookie at all. Just add the following lines to your View Cart code on every page, just before the "// -->" line in the standard code you obtained from Seller Admin:
function EJEJC_config() {
EJEJC_CDAYS = 0;
}
In this case, buyers could add an item to their cart, calculate shipping/tax/discounts, and proceed to checkout as long as the cart is displayed, but as soon as they close the cart display, their cart would reset to empty.
A different way of going about this would use our Buy Now button to bypass the cart and take the buyer directly to instant checkout for just one item at a time. While this means we could not calculate shipping in our cart before checkout, you could just include "free" shipping in the item's price, or you may be able to have PayPal add shipping during checkout. In the latter case, make sure you enable Shipping/Buyer's Address in the product's settings at our end, and when you set up Shipping Methods in your PayPal account, you may need to set "Use the shipping fee in the transaction instead of my calculator's settings" to NO.
