A more thorough explanation:

Catching bargain is an agreement to purchase real property or loan money secured by real property from a person who has an expectant or reversionary interest in the property on unconscionable terms. This means that the terms of the agreement are unfair and unreasonable.

• John is in financial trouble and needs money urgently. He agrees to sell his house to his friend, Tom, for half its market value. This is a catching bargain because John is in a vulnerable position and is being taken advantage of by Tom.
• Susan is a landlord who rents out apartments. She makes her tenants sign a lease agreement that includes a clause stating that they cannot sue her for any reason. This is an illegal bargain because it is against public policy to prevent someone from seeking legal recourse if they have been wronged.

These examples illustrate how catching bargain and illegal bargain can be used to exploit vulnerable individuals or circumvent the law. It is important to be aware of these types of agreements and to seek legal advice if you are unsure about the terms of a contract.