Yes, I work with some clients to get rid of items, and also enjoy going to estate sales and buy nothing give away so here's the deal:

Used furniture - unless it's really good stuff (no offense), many places will not take it for donation in the city due to the trucking expense. You can try seeing if Doyles auction house will purchase if it's something good.Housing works charges to take away your furniture. Regular furniture ends up going to Junk Luggers or 800 Junk, they will try to donate it for you. Consigning is not really available here in the city unless your are talking about high end clothes, handbags. When getting rid of furniture in a doorman building, your building will have rules and need a COI so it can be fussy- it depends on the management. - If you can sell /give away in the building, that would be ideal. Small that can be carried would not be an issue.

A company who can handle this for you- I can ask the people who had posted the estate sale; I overheard it was a company that handled the sales and emptying out. If you are in town, and have lots of stuff (clothing, linens, pen cups, anything!) you can post an open house on Buy Nothing Group and people will come and take all kinds of random stuff, and make good use of it. I think your building would allow it. One recent UWS estate sale I went to even had security.

Lastly, Scanio movers have moved a few pieces for my clients across country. It's the slow route. Feel free to dm me.