1950 Twenty Dollar Bill

If it turned up in a bank it can't be in truly "PERFECT" condition as understood by banknote collectors. In circulated condition, as it is is, it has no added value. Even a Choice Crisp Uncirculated one is only worth about $25 -- if you can find a buyer. And those don't turn up in banks.

I always found the 1950 series bill interesting--it looked to me as if the ink were darker than was case with later issues. Contrex is correct, of course, that only coins and bills which have the appearance of "uncirculated" specie and notes have any significant value beyond their face value.

Go find the website for Heritage Auctions. They always post "prices realized" for all sorts of stuff. They are a large auction house specializing in historical, and natural history collectibles.