question - webpages listing for selling/renting condos - how much to charge?

[2Design]

I was thinking of making an offering to those who have listed on our clubhouse bulletin boards
Currently I have a site I built for their computer club with links to good resources

Idea#1 - listing rental/sale of maybe 5 or 6 lines about the condo/price and their phone number for $5 or $10 a month
Idea#2 - Listing with 1 to 5 pictures - they would get the 5 or 6 lines and a link to pictures of their condo for $15 to $25

Not sure about the prices since the web pages would be a chance find but it would be something they could reference but not as big as newspaper circulation -

Just looking to make some extra money - but the bandwidth and traffic could bog down my host - just not sure
there were probably 10 to 15 rental listings and about the same in sales