TheCartPress is available with some shortcodes.
[ tcp_buy_button post_id=99 ]: This shortcode shows a buy button. If the parameter post_id is omitted then the shortcode shows the info about the current product (post_id is the product id).
[ tcp_price post_id=99 ]: This shortcode shows the price. If the parameter post_id is omitted then the shortcode shows the price of the current product (post_id is the product id). (since 1.0.9)