Free: Contests & Raffles.
I don't have enough sheds to share yet but let me know if you want to get together to hunt sheds (train).Also see my thread on Shed Dog Hunting http://hunting-washington.com/smf/index.php/topic,116389.0.html
E-bay has tons; my local Pets Mart has cut up ones so maybe give that a look
Saweet! Ebay I go! I found like 10lbs of whitetail antlers for about 60 bucks which didn't seem horrible to me. Should be enough for her to chew on and get used to then search around the property for!