Hard to say as the prices have not been consistent. I've seen them range from $40k-$88k the last couple of years at the large auction houses. I'm not sure what happened with $88k 40th. It was an owner modded car and yet the price soared. The majority of the cars have been in the &45k-$60 range. eBay is not a good reference , they are listed from time to time. However, it is rare to see a 40th actually sell there.
Woth any luck, you will find someone that would like to add the 40th to their stable.
GLWS Keep us posted