A professional fraudster can obtain enough details to cost you , everyone on your computer and everyone you have ever spoken to a lot of money and compromise you for a long time.
If there are no details on there or on your selling lists etc just get rid of them.

A friend of mine once responded to a Nigerian scam to "tell them off" and it cost him two computers and a complete new identity to get away from the damage.
They are cleverer than the average computer nerd so just avoid it.

You must treat every spammer like a complete mastermind and avoid them completely.

" I know that they are not trying to scam me, my items are only dollars."

That is not the truth, every scammer does it to make money and you are foolish if you think you can beat them.