Hi Julie,
If you can post the specs of your mattress (see the rules for a “for sale” listing here) and the price you are asking then I can switch your post to a new topic with the name of the mattress and put a “For Sale” in the title (and add your email back in as well).
I’m assuming it was one of the mattresses you mentioned here?
Depending on what you currently have underneath it … there may also be some options that can lower the height of your sleeping surface as well.
Phoenix