Websorcery

This plugin automatically hides the “Add to Cart” button for WooCommerce products that have no price set (or empty price). Instead, it displays a customizable “Request Price” button that opens a lead capture modal.
Features: 
* Automatic detection of checking empty prices. 
* Lead capture form (Name, Phone). 
* Email notifications. 
* Customizable design via settings. 
* GDPR compliant checkbox. 
* Localization support (i18n).

Websorcery Request Price

Replaces "Add to Cart" with "Request Price" button for lead generation.

Epsiloncool

Whenever you plan to begin developing applications on WordPress using AJAX technology, you have to solve a number of 
minor issues unrelated to the logic of your application:
<ul>
<li>How to package and transmit data from the browser to the server, so they will not have been distorted?</li>
<li>How to transfer data, if they are multi-dimensional array?</li>
<li>How to implement a custom processing of AJAX response in case, again, it represents a complex set of data (a typical 
example – form sending and on-server validation)?</li>
<li>How to handle data transition errors?</li>
<li>How to debug all this stuff?</li>
</ul>
Usually these issues generates a lot of spaghetti code, moreover, each new request type requires some customization of 
code. Managing all of this, you forget about the function that you would like to implement.
AJAX Manufactory plugin for WordPress have most of these tasks already solved. You can think about functionality and 
business logic instead.
What you can have from the box:
<ul>
<li>A simple function at the client side which allows to send any your complex data from javascript to WordPress server 
side.</li>
<li>An AJAX response wrapper at the server side which gives to you sent data as PHP array and allows you to create 
an AJAX response as a set of simple “commands” like “make an alert”, “set up javascript variable”, “put html text to 
specific html node(s)”, “execute a javascript function”, “go to specific URL” etc.</li>
<li>Automatic execution of “commands” queue at the client side. Additionally you can specify your own callback.</li>
</ul>
<h4>Documentation</h4>
Please refer <a href="http://e-wm.org/ajax-manufactory/#documentation" title="AJAX Manufactory Documentation" rel="nofollow ugc">Documentation</a>.

AJAX Manufactory

Putting "interface part" out of your mind, you can always concentrate on the logic itself. It is increasing programming productivity and lower human errors.



This methodology is good

This plugin allows you to create AJAX applications by simple way. It implements JSON data transfer, data escaping, error handling.

Websorcery Request Price vs AJAX Manufactory