Can I bargain on price with consignment store?

I am about to make a sell to an online consigner. She made me decent offer except one. So I wrote back stating my lowest price for the particular bag. I don't mind keeping it, if we cannot agree to the price. I think, you can work with them. Keep in mind that it is about 50% of what they will eventually list in their store. Buy out is about 20% - 30% less than consignment.