@Old collector wrote:
Interesting point. As I read it, what you say is true, if: "You donate tangible personal property
with a claimed value of more than $5,000...".
What I didn't see is if that is $5000 total per year, or $5000 per charity in a year.
First of all, the requirement that you can only deduct your cost basis applies to all tangible personal property put to an unrelated use, not just property valued at more than $5000. See "Giving Property That Has
Increased in Value" starting on page 11, and especially Exception 5a on page 12. The $5000 limit dictates when you must include a form signed by an appraiser and an official of the charity.
As far as when is the form needed, this is part of the IRS instructions:
Deduction over $5,000.
You must complete Section B of Form 8283 for each item or group of similar items for which you claim a deduction of over $5,000. (However, if you contributed publicly traded securities, complete Section A instead.) In figuring whether your deduction for a group of similar items was more than $5,000, consider all items in the group, even if items in the group were donated to more than one organization. However, you must file a separate Form 8283, Section B, for each organization. The organization that received the property must complete and sign Part V of Section B.
For example, coins worth $6000 are a "group of similar items" and must be reported with an appraisal and signed form 8232. If you donated the coins to two different charities, you need two forms (one signed by each charity) because the total is more than $5000 even though each charity received less. (But again, if the charity is going to sell the coins, that is an unrelated use, and you can't claim the appraised value but only your cost basis.)
Also, I have seen questions here from people who might have given away all the contents of their parent's house after they died, clothing, used furniture and so on, and did not get an appraisal. They might ask "Can I call used clothing one group, and used furniture another group, and used appliances a third group, and if each group is $4999 or less, I can deduct the entire donation without an appraisal?" I don't have a legal answer, but in my lay opinion I would consider that significant risk if they were audited. So I would be cautious about trying to donate more than $5000 of a collection without the proper documents, even if you split it among different charities.
