I agree with the others in that games north of 10K are probably going to take a little bit to get the right buyer lined up with appropriate funds. The other item is that it seems that Spooky games are very popular in the upper midwest, so I think there are a larger number of collectors in the area that bought Rick and Morty, limiting the pool of potential buyers of your machine. Be patient, the market will speak on if your price is spot on or not.
FWIW, I really enjoy my R&M and would be among the last three games to leave my collection.