I've ordered from Mr. Miranda a couple of times. He imports more unusual varieties and selected strains that can be pretty pricy. That being said, I agree that the plants you've shown are very small, even among the seedlings he sells. I did order a different C. amethystoglossa aurea a few months ago and they were much larger. I'm glad he's making it right for you.
I don't have a photo of the C. amethystoglossa but here is peloric C. leopoldii. I circled the size at the purchase in blue.