How much does KYC cost?

Good day, I'm curious about the cost associated with Know Your Customer (KYC) procedures in the cryptocurrency and finance sector. As a professional practitioner, I understand the importance of complying with regulatory requirements, but I'm interested in knowing if there's a standard fee structure for KYC, or if it varies depending on the service provider, the complexity of the process, and the size of the business. Additionally, are there any hidden costs or fees that businesses should be aware of when undergoing KYC? Your insights would be greatly appreciated.