I have one new DUO-M2 Sega Genesis Model 2 Power Adapter listed for sale here:
https://www.ebay.com/itm/RetroGameCave-DUO-M2-Power-Adapter-Premium-Sega-Genesis-Model-2-Sega-CD-Adapter/143029332841?hash=item214d366b69:g:XnAAAOSwkFZb~Jk-
The awesome thing about this power adapter is that, it powers both the Model 2 Genesis and Sega CD with one Adapter. Freeing up one socket in a power strip. It is also very well designed.
I am selling this adapter for $20 with free Priority Mail shipping. If you have been wanting to get one of these, here is your best chance.