The consignment shop works sort of like a shop in WA. I went there late at night, and it was greyed out, so I went back the next morning, figuring it had normal working hours, and the shop owner was there. You can click either him, or the cash register, and choose buy. Then in the info that comes up, press the sell tab (or something like that) and it's like selling stuff at the grocery store, but you don't get the money straight away. You get money later when it sells. But watch out - I find that sometimes what you sell at the consignment shop doesn't count towards money experience with self-employment. I found that with nectar, and I think someone else had that problem with something else too.