A couple ideas....
1. If she wants to buy them from a grocery store, I'd contact the manager. First, they can make sure they have enough on hand, and two, it's likely they'll be able to offer a better pricing.
2. It's likely she'd get a better deal going through a restaurant supply company. I'd contact the PR person for one of her favorite restaurants and tell them what she's trying to do. Would they be willing to order the turkeys for her? I bet they would. (I've had good luck with this strategy.) Because they can get better pricing through volume, I bet they can get her a good deal. (Plus, they may want to jump in on the fun and do a match of some sort...)
3. Another option...if she's going through Costco, again I'd contact the manager and/or their PR person. They'll be sure she gets the best price.