Due to it being sort of rare--
In the old days, there was a scandal somewhere about a politician buying votes with $2.oo bills.
Back then, if you spent one, everybody thought you'd sold your vote.
After that, they became unpopular, and nobody wanted them.
In later years, like those dollar coins about the size of a quarter, they just never took off.
The value is probably a few bucks more than two Silver Certificate one dollar bills go for now.
Check the govt. website or somewhere-- I'd guess it to be worth about $25.oo.