-30% production balancing with -20% purchase price in gold/faith. Your Trade Route capacity is enhanced EACH TIME you enter a golden age (which mean, if you have only one city with one market but you entered 3 golden ages in a row, you will have 5 TR capacity, as far as I understand). CH have bonus gold from HS and built in less time. Your cities will be in desert, so your TR will easily have a +7 gold besides the normal bonuses.
I know that there is a lot of drawbacks, but I think it's well balanced. IDK if it's enough, if it's too weak or too strong, but it's new and seems fun to play.
And I can guarantee we will have pages and pages of people complaining that Mali is "the worst CIV ever (after Maori, Canada and Georgia) because production loss!" because it does not fit their formated gameplays.