If priced 10% below market value, you should offer $40,000
If priced at market value, you should offer $39,900.
If price above market value, you hould offer $Market Value.
What is Market Value?
What a willing seller and able buyer agree upon.
As others have suggested, condition, motivation, terms, are all components of 'market value' to the buyer and the seller. It is highly likely all purchases at this price point will be cash. This is important to understand should you elect to believe 'cash is king' and attempt a low ball offer.
Such a property in my area means it's a knock down. The value becomes related to my future intention for that piece of real estate.