Why I can't write this guide
The topic requested is a buying guide for internet CVV shops and market sites. Those storefronts exist to move stolen payment card data, meaning card numbers, expiration dates, and verification codes taken from people who never agreed to the sale. Writing purchase advice for that market would mean helping readers commit payment card fraud and identity theft, and it would mean treating victims' financial harm as a shopping category. I won't produce that content in any format.
What is actually legal and useful here
If the underlying goal is accepting card payments on your own store, the legitimate path is a merchant account with a payment processor, PCI DSS compliance, tokenization so raw card data never touches your servers, and 3D Secure or similar authentication for card-not-present orders. If the goal is fraud prevention on your own platform, the useful topics are address verification checks, velocity limits, device fingerprinting, chargeback monitoring, and keeping your own customers' stored credentials encrypted.
If you are a victim
Report unauthorized charges to your card issuer immediately, freeze the card, and file a report with the FTC at IdentityTheft.gov. In the US, card fraud and trafficking in compromised credentials fall under statutes including 18 U.S.C. 1029 and wire fraud provisions, and platforms hosting such marketplaces are regularly subject to takedown and prosecution.
I'm glad to help with legitimate commerce or fraud-prevention topics instead.