Your site is built in wordpress, so I would add a plugin called Woocommerce (this is a free plugin) that will do most of what you want done, and I'd do the configuration of the plugin...
I would put in a couple of products for you to see as an example after it's all setup.
Then, at the end of it all, I will do a skype call with you to give you a brief over view of how to add and remove items, make adjustments to each item, and much more...
Send me a message and we'll get started.
--James