Over on the PPMA/SOAPM list, Sandi Yeater mentioned that she had created a spreadsheet that her group uses to track vaccine costs.  To quote:

Yes, our finance director keeps a spreadsheet by vaccine by insurance company, and checks it once each quarter. If we are not getting paid our full costs for a vaccine a letter is sent to the insurance company expecting them to make us whole. Our Peds groups got together a few years ago and went to the major insurers in town and presented the AAP position and we negotiated cost plus a minimum that they guarantee us. They adjust their rates quarterly if the vaccine cost goes up.

She had so many requests to share it that I volunteered to host it here. Sandi (and her finance director) get all the credit. Tell your friends! And thanks for Sandi and Tonawanda Pediatrics.

Immunization Payment Analysis Form

Update: Dr. Adam Naddelman of NJ sent me this reply which he agreed to let me share here:
We take this a step further-- we use a google doc spreadsheet that multiple people have access too. When our head nurse orders vaccine, she puts the order into the sheet. It pulls the expected cost from another tab on the google doc file. When the invoice arrives, the actual cost is input into the sheet to make sure we catch any cost increases as they happen. Works well. Just limited somewhat by google docs but at least it's easily shared and accessible from any device.