I checked out the price of gruit, or really the wild spices from which it is made. At least in small quantities it is still many times the price of the most expensive(rare) hops.
I guess an herbalist could go out in the woods and find the plants on their own...but of course this would only work for homebrew quantities.
At present, it would be much more expensive, but it does stand as an option should hops go the way of the barrel of oil.
Where there’s a will, there’s fermentation.