You can either dissect the inner workings of ajax calls (if the website has any) or write a regular full-page scraper which traverses the product catalog. Popular choices for scraping are casperjs, beautiful soup, mechanize, etc. Each having its strengths and drawbacks - casper for instance can e...
If you simply aggregating information than I don't see any issues with copyright. But, I would seek permission from the brokers/website owners to make sure business is protected. It doesn't hurt asking for permission, and if it directly benefits them to get leads/sales than none of them will say no.
It does violate the TOS for most social sites and PPC advertisers. Additionally, you're not doing your end customers any favors because you are selling them access to crap contacts who are not necessarily interested in their product. Don't do it. Build your own targeted list of 1000 legitimatel...