Tax delinquent properties, do they exist? 200k home for $50k?

[Doanh Mai]

My first time hearing about acquiring a tax delinquent property was actually from my tenant. His story is that he works for a construction company that renovates these types of property. He was saying that these properties can be auction off at a ridiculous below market price. I am so new at this. Can someone confirms the validity of these type of deals? How easy is it to buy them? How and why do they exist without the big investors all over them and bidding up value so they become somewhat market value?