I've both manually added the number and done a search from the bidslammer site for "asus q87m" and picked the right one.
It gives an invalid item # error. It also shows the shipping at free which is incorrect.

Hello Rudi,
Thank you for your question about the "invalid item" error. Please provide the item number if you have it, and we can look into this for you.
As a first check, we always enter it into the eBay.com search box to see if it comes up. You might try that in case there is a typo somewhere.
Please let us know the item number, and we can take the next step.

384202365934?epid=170033785&hash=item59743edbee:g:EugAAOSwIdNguNYG">https://www.ebay.com/itm/384202365934?epid=170033785&hash=item59743edbee:g:EugAAOSwIdNguNYG

We addressed this after your reply. If you still have issues please let us know.
Please let us know if you have any other questions, or require other assistance. We are happy to help.