Interesting dilemma: liquidation percent off?

[swarmee]

So I've had a booth in an antique mall in Destin for the past 2.5 years. On Monday, someone traveling through the area stopped in and reviewed the items in my booth, where I have probably 100-150 cards priced between $50 and $500 each.

He asked the mall employees to call me to see what discount I would give on the entire lot. Figuring there were probably at least $10K in list prices, I said that I would give a 40% discount on the entire lot. He then decided to select a smaller group, totaling $3,300 in list prices, and called back to see what I would give as a discount on this group. I responded $2,500, basically 25% off. The buyer passed on both options.

So, what type of bulk discount on this type of lot would you have offered? What discount would have made you take the whole lot?

In my case, I probably have half the list price invested in each of the cards for sale. So if I buy a card for $200 intending to resell, I usually would price it at $400 and wait for it to sell, as Destin is a great location for vacationers and gets really busy when it's raining on the beach. And when an item sells, the mall would take a 10% of sale price as commission. So if I sold $10K in cards at 40% off, I would get $5,400 on the sale (well, subtract another 3% - $165 - if they pay with credit). So the 40% off discount would have guaranteed me only a slight profit.