note if you gift it to them, you will need to provide them with your basis because they will need this if they sell. if they sell then the gain is measured by the difference between net selling price and your basis.
if selling I would get an appraisal, so you can justify the sales price if the IRS comes calling.
there is no requirement that you sell at fair market value. you can do partial sale and partial gift.
basis in part gift part sale
https://www.law.cornell.edu/cfr/text/26/1.1015-4
