:welcome
i don't have any specialized knowledge but i agree with you. of course they need to protect their trademark and any domain name with the name google in it could be a problem.
but i also think you are right to ask for money. you went ahead and shut it down, so you are not hurting their trademark anymore now.
go ahead and reply to them with what you want. tell them how much money you want and why. they might be reasonable.
I definitely think it's worth fighting them.
Goldgoogle.com isn't a word at all, and not a word that Google owns. Make them pay you.
