Doug hosting is cheap, building and maintaining is another story and usually not cheap. If you build it yourself you can get it for $8 a month. They offer better rates for longer commits but I wouldn't go past a year. This is the host I currently use.http://www.jaguarpc.com/r.php?a=143207.97
Many of these hosts offer "website builders" however you have to be very careful because they are often proprietary systems. Moving the site becomes an issue, you can usually move the files but the backend that is used to maintain those pages will no longer be available on the new host so you'll have to start from scratch.
What you can do is install something like Joomla which is an open source content management system. If you want to move your site to a new host the files and the database go with you. http://www.joomla.org/
That software doesn;t require any coding knowledge and is even often used by professionals to build websites. If you want to play with this locally you can first install XAMPP which is basically an apache server for local testing which is going to be almost exactly identical to what you'll need to know , it includes php and mysql and everything else you need.http://www.apachefriends.org/en/xampp.html
As far as your specific needs for Realty I'd have to know what resources are offered such the listings before I could tell you how you would go about integrating it.