We shouldn't be move by mere tricks in the market, some are designed to deceived traders into giving out access of their accounts while some will make jokingly results of you. Unimaginably because bitcoin can't be free, not that large quantities. I would advised to leave anything that you don't understand and focused on a more legit way to make significant earnings from bitcoin, either through trading or investing to get more. You're 100% correct, no one will give you bitcoin for free, rather it's definitely you're going to work for it before you earn it, there's no free bitcoin elsewhere.

If those wallet files were real, they would have never sold them.

Every single case you see on the internet is either malware that is intended to steal your coins or is simply an empty wallet file manually modified to look like it contains keys to popular addresses with large balances.