I'm always surprised how hard it is to get artificially sweetened yogurt. I know of only one brand at only one chain of grocery store in my area. It seems like a natural combination.
I've been eating whole fat greek style US yogurt lately. It tends to have less sugar than other plain yogurts and I am less inclined to add it.
Fresh yogurt is also naturally sweeter
I would recommend more people try it. It's generally better than store bought plain style yogurt and super-cheap.
I can get a gallon of milk (on sale, non hormone BST stuff) for about $2 (in CO, US). That will yield the same in yogurt (4 quarts.. I use quart mason jars).