I'm late in Universe 2. It seems neither the auto-purchasing of Merge Gems, nor the price reset on Singularity, is functioning. The Gems are only bought manually, and the price has never gone down.
I noticed that too. I don't think it'll get fixed though. If you don't know the dev, he makes games, updates them maybe once or twice, then leaves it alone for the rest of ever and makes another game. Probably won't get fixed
Recently discovered that this is, in fact, intentional. If you delete gems, the price goes back down. The milestone and price reset seems to be left over from U1.