WHMpress offer highest level of flexibility. It allows you to customize shortcode defaults from WHMpress > setting shortcode defaults and then allows you to override these defaults while inserting shortcode.
Pricing table is a composite shortcode, it includes product name,description,price,price combo and order button shortcode. Pricing table (and all composite shortcodes) will use default values for the shortcodes used within it. You are able to customize Pricing table itself through default values or through menu while inserting the shortdoce. But to customize order button or pricing etc, you will need to change the default values of pricing and order button.