I hate to sound like a douche, but when it comes to names, plural "ing" words are about the worst kind. They're just off-putting and really not even worth having. Anyone who actually uses names like that usually have that tryhard personality.
I can't imagine Gamblings being worth more than 5m. "Gambling" alone wouldn't even be worth that much. I know it sucks, but the world of rare names has become a very shallow one.