The domain name "hamer.com" was grabbed in 1996, along with thousands of other family names, by a company called NetIdentity. 

NetIdentity's website tells us:

"In 1996, the founders of NetIdentity registered over 15,000 internet domain names, a combination of 13,000 popular surnames and 2,000 category names. By owning these names, NetIdentity can provide email and website hosting services at these domains to anyone for a small annual fee. For example, we own www.smith.net and can offer anyname@smith.net as an email address and www.anyname.smith.net as a website address. Simply search for your name and sign up today!"

NetIdentity says that it is not prepared to sell any of these names.  When I wrote to them about "hamer.com" they replied:

"Thank you for your inquiry into a NetIdentity domain. However, we are not interested in selling our domain names. They are for the current and future use of our customers. ... If you are interested in a personalized email address with the domain in question, please visit our website at http://www.netidentity.com to check on availability!"

I assume that their policy applies even to companies with well-known family brand names (such as Hamer Guitars), who clearly have a stronger claim to the domain than NetIdentity does.

Obviously "not prepared to sell" may mean "will sell for an obscene amount of money".  Alternatively, you could try taking them to court under the Anticybersquatting Consumer Protection Act, which may or may not be cheaper.  (Section 3002(a) of the Anticybersquatting Consumer Protection Act prohibits bad-faith registration of domain names.)  Several celebrities have been successful in liberating their names from cybersquatters.

If you are planning to have a go at getting "hamer.com" away from NetIdentity please let me know (malcolmhamer@hotmail.com).  I would be happy to write a letter of support for you to present with your case.