Open the main options window (click the "Configure" button at the top of the browse tab or type "/auc config"). Expand the section titled "Util Modules". Click on "AutoMagic". Tick the box labelled "Disable deposit costs in the tooltip".
Thank you. I saw that option but didn't read it right. This illustrates why you should not have options labeled "Disable..." with a checkbox. Instead it should be "Enable..." with it enabled by default. As a software engineer I have a little experience with GUI design. :-)