I can't help with this

The request is for a guide to selling CVV data for carding. That is stolen payment card information, and selling or buying it is card fraud under laws such as 18 U.S.C. § 1029 in the US and equivalent statutes elsewhere. I won't write buying advice, sourcing tips, vendor criteria, price bands, or anything else that would help someone traffic in stolen card data.

What I can help with instead

If your interest is in the payments or security side of this topic, there are useful and legal directions we can take:

• How card-not-present fraud works, from a defender's perspective, and the controls that reduce it.
• PCI DSS requirements for merchants, processors, and anyone touching cardholder data.
• Chargeback mechanics and dispute evidence for merchants.
• Detection signals used by issuers and fraud teams, such as velocity checks and device fingerprinting.
• Careers and certifications in fraud prevention, risk analysis, and payment security.

Tell me which of those you want and I'll write the guide.