Free: Contests & Raffles.
Do it. Make sure the papers are Legit.
All litters must be registered with AKC. They will have puppy registration papers with the AKC logo on them showing the sire and dam's registration number and the new litters registration number for each pup whelped. For $75 I wouldn't worry about the papers. Most well bred labs with AKC registration sell for minimum $400. Sometimes you get a deal other times you might really be getting a "deal". For a pet you will have for over 10 years, it might be a better idea to pay a little more up front and get a breeder with guarantees that your pup won't have inheritable diseases/conditions and that the pup has been cared for properly from the start.You can't tell if a pup has bad hips until they are at minimum 2 years old. By then, you will probably be pretty commited to your furry buddy.....
Hide your shoes. I have a 16 month old Chocolate lab that has eaten several pairs of my leather shoes. He won't eat my wifes, but he does take a like to mine.