A QCD question

I use and Understand Qualified Charitable Distributions from my TIRA, which I’ve used each year after I was 70 1/2 years old. But I came across a situation that I don’t understand and can’t seem to find an answer to.

A 501c3 charity raises money by accepting material or services donations that it then puts up for bid on an auction web site. The IRS rule is that any charitable donation amount must be reduced by any benefit or item received by that item’s fair value. So if I bid $100 for a dinner for two and the meal we get is priced at $60, then I must reduce the deductible charitable contribution by that $60 to get the charitable deduction amount of $40. But how would this work with a QCD? Would I do the same thing? So in this example, I contribute the $100 thru a QCD, as it is going to a 501c3, but then reduce the QCD amount thus a corresponding increased amount on box 4b by the value of the dinner?