If I think the value of the donated items is $4,000 - Am I required to get a professional appraisal done? Or can I just deduct the $4K and fill out form 8283? Goodwill only provides "estimates" of what a random t-shirt would be worth. They don't estimate what an Armani shirt that has only been worn once & originally cost $150 would sell for. In addition, as far as I know, you only get a receipt from Goodwill that says you donated - you don't get a valuation or list from them. Some more details to this would be appreciated.
You may be liable for a penalty if you overstate the value or adjusted basis of donated property.
The value or adjusted basis claimed on your return is 150% or more of the correct amount, and
You underpaid your tax by more than $5,000 because of the overstatement.
The value or adjusted basis claimed on your return is 200% or more of the correct amount, and
You underpaid your tax by more than $5,000 because of the overstatement."
So, you should be very careful in valuing these items. In my opinion, you should take no more than 10% of the purchase price.
But, for the dollar amount you are planning to donate, you must adhere to the following;
If you claim a deduction over $500 but not over $5,000 for a non cash charitable contribution, you must have the acknowledgment and written records described under Deductions of At Least $250 But Not More Than $500 . Your records must also include:
How you got the property, for example, by purchase, gift, bequest, inheritance, or exchange,
The approximate date you got the property or, if created, produced, or manufactured by or for you, the approximate date the property was substantially completed, and
The cost or other basis, and any adjustments to the basis, of property held less than 12 months and, if available, the cost or other basis of property held 12 months or more. This requirement, however, does not apply to publicly traded securities.
If you are not able to provide information on either the date you got the property or the cost basis of the property and you have a reasonable cause for not being able to provide this information, attach a statement of explanation to your return.
Just be sure that whatever amount you value your donation, it falls within the guidelines and keep written proof ( and pictures if you can) of the items to show that your items would be worth more than average donated items.
Hope this helps.