I just realised i probably got ripped off.

About 2 weeks ago i logged in to my old profile after a while. This profile is 4 years and 10 months old. Some random dude in Crimson Armor approached and told me he wanted to buy the Strong Dragon Armor i was wearing cuz it looked neat. I thought whats wrong with that guy but I could use the money. So i sold it to him for 25 mil thinking it was a good deal.
Now it dawns on me that i died all my armors back when i played in early summer 2020.
Just about how much money could I have blundered with this move?