2005 545i in the begin I couldn't find the oil leak it was begin burned up by the engine now heavy oil leak like if everything came out

Oil was being burn up by the engine cause I could never find and oil had the car sitting
out side my house parking lot over the winner started the engine parked it in front of
house next day go to take for ride oil leaking like crazy and don't know if it's a loss hoes
or if oil pan broke how much would something like cost