viewup

The plugin allow you to select a post type to be the products and a meta name to be the price. 
With shortcodes, you can add a ADD TO CART button and a CART PAGE. 
The plugin integrates with <code>contact form 7</code>, allowing you to insert on your contact form the user cart.

UP WP Cart

Simple cart plugin for WordPress, with Contact Form 7 integration

jimmywb

This plugin makes a widget available which allows you to add a simple link list (bulleted or numbered) to a sidebar.

Simple Link List Widget

This plugin makes a widget available which allows you to add a simple link list (bulleted or numbered) to a sidebar.

UP WP Cart vs Simple Link List Widget