When you visit the web name: example.com, is the name developed? If it is, it would probably not be for sale.
Is it parked? If it's parked, is there a for sale sign and offer form? You could make an offer this way.
If there is no way to contact the owner through the page, perhaps the domain name does not even resolve, then find the contact details for the owner via whois, and make an offer via email.