This extension removes displaying of prices for products with "0" values( or negative values per your product management convenience) and changing "Add to cart" button into "Inquiry" button, that with clicking, will redirect to contact form.
This price Inquiry contact is pre-filled with logged-in user data(or empty for guest visitors) and added with product name as subject field of contact form.
Email messages are delivered as with standard default OpenCart mailer.

Supported all default modules and template layouts. Add-on for extra modules can be updated on demand.
Easy install no files will be overwritten, installation info provided with download

Multi currency supported.
This modules actually replicates several functionalities as pricing quotations, specific product enquiry, price on demand etc.