Yes, you might have made a mistake.
You recently purchased a used Ryzen 5 1600 for $100. Many others are charging high prices for similar models.
In the United States?
It wouldn't seem like a poor offer overall; they match the price of similar items on the used market when you locate them.
Yeah
You might have bought a brand new Ryzen 3 3100 for $120, but at $100 the 1600 seems to offer the best deal currently available.