Translation

• cannot afford
• can't afford buying

Examples

• 他买不起汽车，更不要说买房子了。
  He cannot buy a car, still less a house.
• 我买不起自行车。
  I could not afford to buy a bicycle.
• 那辆车子太贵了，我买不起。
  The car is too expensive for me to buy.
• 我买不起300块美元以上的照相机。
  I cannot afford a camera above 300 dollars.