I belong to another golf club and pay GHIN fees there. Can I get a discount on my FHGC GHIN fees?

From the Washington State Golf Association website:

If you have paid for a Washington State Golf Association Membership at more than one WSGA Member golf club and were issued the same GHIN number at each club, you are eligible to receive a rebate of $10.00 for each membership beyond your first one.

You can find the rebate form on the WSGA website.