The "kilogram" is not a usual measure of money! (Just teasing, you're reporting what's on the manifest.)

For the curious, US bills weigh almost exactly a gram, and other currencies seem to weigh the same or somewhat less.

So 50 kg of $100 bills would be $5 million, or if it were $1 bills (very unlikely), it would be $50,000.

Other currencies would vary in value and density, but it's likely this was as much as millions of dollars.