Parable of the tower

Luke 14:28 For which of you, intending to build a tower, sitteth not down first, and counteth the cost, whether he have sufficient to finish it? 29 Lest haply, after he hath laid the foundation, and is not able to finish it, all that behold it begin to mock him, 30 Saying, This man began to build, and was not able to finish.