Mr Birling

• Arthur, you're not supposed to say such things'- Mr Birling not being sure how to act like a high-class citizen highlights the fact that he has worked his way up to the upper class. Perhaps this suggests that Mr Birling is merely a product of his environment.
• "I'm delighted about this engagement"- Mr Birling

  .He is only delighted because their engagement means that his company will merge with an even bigger/more successful company. Therefore, he sees the engagement as a business deal instead of a proclamation of love. This highlights the selfishness of Mr Birling as well as the bourgeoisie.
• "lower costs and higher prices"-Mr Birling

  .Highlights his greediness and selfishness as he wants people to give him more money while he keeps as much money as possible. This kind of thinking is what encouraged the worker strike as businessmen cut costs at the expense of many proletariat workers