Luke.14.28  For which of you, desiring to build a tower, does not first sit down and count the cost, whether he has enough to complete it?
2Cor.11.7  Did I commit a sin in abasing myself so that you might be exalted, because I preached God's gospel without cost to you?

Hyper-concordance v1.1, by Sean Boisen. Scripture verses taken from the Revised Standard Version, copyright 1952, 1971.