It could be argued that Abram’s folly was worse because he did it twice. Look at:
The first time he did this was just after God had called him and Abram had responded. The second time was after the Lord had promised Abraham that Sarah would have a son. It was after Abram had believed God and it was reckoned to him as righteousness, Genesis 15:6 (here @ Bible Gateway).
Think of that for a bit. Abram, Abraham, had followed God, believed in His promises, and yet in the matter of Sarai, Sarah, did not trust God to protect them.
It leads me to think that no matter the closeness of our relationship to God, the fidelity of our obedience to Him, that there will always be those areas of our lives we hold back from Him. That may be why we read David’s oft repeated cry for the Lord to revive, teach, lead, and instruct him in Psalm 119 (here @ Bible Gateway).
Regardless of how close we are to Him, we are completely dependent on Him to trust and follow. Not to recognize this and proactively pray against this type of behavior, leaves us open to duplicating Abraham’s folly.