If a same sex couple wants to use a bakery for their "ceremony", there's nothing in the law that prevents them from quoting a price of $5,000 for the cake, to include a nonrefundable deposit of $4,000.
If the LGBT bullies seek to persist, the owners can accommodate them by saying they'll donate all profits to the local women's shelter, or another organization of their choosing.
Guerrilla war, not a frontal assault is the way to defeat the enemy.
I don’t think you can do that. Charging a different price based on a protected trait is also discrimination. Just consider a more traditional scenario of a restaurant having a separate menu for blacks with all prices doubled. There is no doubt that the courts would consider this discriminatory.
The only solution I can see is to stop providing service to weddings altogether. It should still be legal to discriminate between a wedding and other type of customers, since “wedding” is not in itself a protected activity.