Your basis/cost should be the lower of cost or FMV on the date you received them. If you had said $0 cost and had recently gotten them, Normally items do not appreciate and IRS has a rule:
Rate of increase or decrease in value.
Unless you can show that there were unusual circumstances, it is assumed that the increase or decrease in the value of your donated property from your cost has been at a reasonable rate. For time adjustments, an appraiser may consider published price indexes for information on general price trends, building costs, commodity costs, securities, and works of art sold at auction in arm's-length sales.
Hence why you should be careful in entering your cost basis.
**I don't work for TT. Just trying to help. All the best.
***Say "Thanks" by marking as BEST ANSWER and clicking the thumb icon in a post and that I solved your question
**Mark the post that answers your question by clicking on "Mark as Best Answer" I am NOT an expert and you should confirm with a tax expert.
