The prices listed for scanning and prints are firm prices. The prices listed for correcting, retouching and restoring photos are estimates based on average costs that you can use to get a fairly accurate idea of the total cost of your project. If after receiving your original photos or scans I determine they will cost more than the prices listed here, I will contact you with a firm quote before I do any work. If the price is OK, I'll invoice you. If it's more than you want to spend, I'll return your photos.
A more complete explanation of why the costs of retouching may vary is available here.