Keep in mind, that the IRS isn't fond of "we did our best to determine FMV".
If audited, not saying you will be or this is a trigger point, the IRS will certainly review your methodology. If they are not comfortable with your methodology, they will challenge your figures and then that most likely will lead to an appraisal by a professional.
Just want you to be prepared ahead of time should it become an issue.
*A reminder that posts in a forum such as this do not constitute tax advice.
Also keep in mind the date of replies, as tax law changes.
