Setup basic property valuation query via zillow or other property valuation API-

Hello, I have a solid understanding of WordPress but I need someone who can give me honest council on how the various available API's can be integrated and leveraged to create unique user experiences on our sites. In short, I am trying to understand them and if possible and practical to use them with our site/clients. Currently, I have a mortgage calculator that is almost finished. It's really special in that it performs a huge number of computations so that the user never has to enter items they wouldn't know such as the interest rate or debt to income ratio. Here is an example: [login to view URL] To round out the experience, I want to add a few more functionalities and frankly, I need guidance in terms of how they can ba accomplished. First, I want to add some type of content locker that only allows them to run one calculation before requiring free registration. 1. I want them to be able to order a home price valuation if desired and have that populate the form. something like Zillow Zestimate 2. Based on the results of the calculator provides, I want to display properties probably via IDX but am unsure how this would happen or if its the best way of accomplishing the goal. I see this as being the start of a truly unique and massively helpful set of tools for prospective homebuyers and sellers. The purpose of this project is both to accomplish the objectives above and equally to develop a partnership with somebody who understands and enjoys user interactivity and who will present ideas whenever new technology makes upgrades to our client experience possible and or affordable. Thank you very much for your time and consideration. We are sincerely looking forward to hearing your ideas.