213,519 bitcoins
That is a massive amount of bitcoin just for a country imagine if they don't discover that one I think criminals will enjoying and harvest right now. Yes, the question is what do the Bulgarian government do with that seized amount of bitcoins? Bulgarian government would be rich by now and bitcoin price would skyrocketing again.
If they are smart they will sit on those coins and will not sell them, they are just going to crash the market if they do, if bitcoin is really the future they may be sitting in one of the largest holdings of bitcoin in the entire world, their country may become a economic powerhouse by just holding bitcoins similar to what happens to governments holding lots of gold.