How to be safe when buying site from flippa

This may sound weird but i once got scammed on flippa . A seller sold me a site for $250 and in the name of marketing material (by which he was earning ) which was supposed to be ad copies and platforms where he published and the things that worked for him he gave me tutorials of link building and email marketing.

So looking to buy a site and how would I stay safe from these scammers? BTW if any of you have a site to sell you can PM me or post here.. I am really serious about buying a site

For $250 it's unable to buy a site with a passive income. Also, you must do your due diligence. With a passive income will cost least $4K. If you go with software website , Saas (except SEO shit package services) you can't be go wrong.

I have sold a software as a website there for 12K and now he's already earning 20K. (When selling i am making $800 passive income and growing ).

I don't sell any website myself i just saying to get the idea. Most of users are buying adsense or amazon affiliate web which is risky than that.