I donated 6 used sewing machines in 2023. I got values for comparable sales of these machines on ebay. Can I use those values in my deductions?

with ItsDeductible, there is a Fair Market Value of ~$20, but the values on eBay are more like $99 - $1000, depending on the machine. This is a big difference. I want to get the most for my donation, but I want to do it legally and fairly, of course.