• Throw in the towel
    To give up on some endeavor; to quit or abandon something; to admit defeat or failure.
    Example: I have been working on this book for over a year, and I am getting nowhere with it. I think I am ready to throw in the towel.
  • There’s no such thing as a free lunch
    Nothing is ever really given away for free, so be wary of hidden charges, motives, or agendas.  The economic theory, that whatever goods and services are provided, they must be paid for by someone – that is, you don’t get something for nothing. The phrase is also known by the acronym of ‘there ain’t no such thing as a free lunch’ – tanstaafl.
  • One off payment
    One-off is something than occurs once and only once, and is not part of a regular process or sequence. A “one-off” payment would be something you make once for some particular charge or fee, and then in the future you might pay a regular fee every month or whatever.
  • Inadvertently
    without intention; accidentally. Example : “his name had been inadvertently omitted from the list”.