McConaughspawn -- Three Million Dollar Baby

Matthew McConaughey's lil' bundle of joy will be making Matt a big bundle of jack.

Our spies tell us OK! mag will shell out $3 mil for the first pics of young Levi, who was just born Monday night. And that's not all -- we're told that the deal includes baby's first Christmas as well.

We also hear OK! gets first right to the pics of the wedding if Matt and Cam get married -- though they'll have to pay extra for those snaps.