Denra.com

Ivaylo Tinchev

There are some products or services that cannot be sold directly via shopping cart. This plugin allows your prospective customers to easily request a quotation from you using a simple and easy to use contact form.
It takes lots of efforts to develop and support a plugin. Please send us your feedback and questions to fix your issue before leaving a bad review.
Are you satisfied by using this plugin? Consider leaving a <a href="https://wordpress.org/support/plugin/really-simple-rfq-form-for-woocommerce/reviews/?rate=5#new-post" rel="ugc">5 star review</a>.
If you need support or more information about this free plugin please read the description and the F.A.Q. section below or write in the <a href="https://wordpress.org/support/plugin/really-simple-rfq-form-for-woocommerce/" rel="ugc">Support Forum</a>.
<h3>Features</h3>
<ul>
<li>Simple and easy to use RfQ form with name, email, phone, questions or comments fields.</li>
<li>Uses AJAX submission and the user does not leave the page while sending the request.</li>
<li>Automatically adds the product name, SKU, picture and link in the request message.</li>
<li>Emails the requests using the built-in wp_mail() WordPress function.</li>
<li>No complicated settings. All is setup to go. Simply install it and it works.</li>
</ul>

Really Simple RfQ Form for WooCommerce

Removes the 'Add to cart' button from WooCommerce and adds a simple 'Request for quotation' form on all product pages.

stasionok

With this simple plugin you can restrict extra external requests made with internal WordPress WP_Http class. 
Just put in the filter rules field what you wish to restrict. One url part or url regex per line. 
By default, the plugin returns WP_Error answer for restricted requests. But you can put in response your custom response data.

ROB (rat out blocker)

Restrict execution of certain external requests with partial url or even regex to prevent personal data leakage (as example)

Really Simple RfQ Form for WooCommerce vs ROB (rat out blocker)