Although that appears to be true for software or paintings you create yourself (see discussion below), I don't think it's actually true for software or painting

Although that appears to be true for software or paintings you create yourself (see discussion below), I don't think it's actually true for software or paintings that you bought. In those cases you would deduct the fair market value at the time of the donation (with some exceptions). This is actually a common tax loophole: you can donate appreciated stocks and get a write-off for the full value, without having to pay taxes on the gains.