If the original Challenger is any indication, the 08’s SHOULD be worth a bit more, due to their being the first and that they are numbered. (The 70’s command the highest prices of any of the first generation Challengers)
What will make the 09s worth a bit more would be the available 6-speed and a wider choice of colors. If someone wants a manual….well the 09 would be the clear winner. I would think that colors would be a secondary consideration.
Bottom-line…they look the same and with the exception of additionally options that came on line in 09, they are basically the same car…. (Just my two cents)