mra13 on "[Plugin: WordPress Simple Paypal Shopping Cart] Price variable?"

I think the following will work good for you:

Create a page called "checkout" and place the shopping cart shortcode on that page.

Next, go to the settings page of this shopping cart and check the following checkbox:

Automatic redirection to checkout page

This way the customer will get redirected to the checkout page after they add an item to the cart (ready for checkout)