In the movie Fargo, automobile sales manager Jerry Lundegard owes $320,000 to GMAC, due to loans he has made for fictitious vehicles. At the same time, he arranges for his wife to be kidnapped for $80,000, with the kidnappers getting half of that ransom and the other half going to Jerry.
Why did Jerry ask for less ransom money than he owed? He could have easily asked for more -- he knows his father-in-law can afford it -- and gotten himself out of his mess with GMAC. (Indeed, he even tries unsuccessfully to call off the kidnapping after he finds a $750,000 scheme.)
Looking for an in-universe answer. Of course, the out-of-universe answer is that it helps to show how pathetic he is.
Related, but does not address the mismatch in the numbers: Is there any hint as to why Jerry needs the money?