Hello.
My name is Maciej, I am a Python developer with over 3 years of experience in developing web scrapers, and other web automation tools. I also have experience with scraping hundreds of sites, including one of the 3 you need (immoscout24h).
I have read the whole description, and I can create for you a tool that will go to each of real estate websites, check if the user is not a company by checking the ending and send them the message using the contact form.
I will develop this using Python3, Selenium, and Anti-Captcha API (if needed).
The settings of the script like the delay between messages and how often should it run will be possible to set in the config file.
I can start right away, and completed in about 6 to 10 days, the price will be 950$.
Message me if you have any questions or want to start the project.
Looking forward to hearing from you
Maciej Janowski