Perhaps Murry Park might have a used one? Just REMEMBER two things. One is to not consider a used cable as a "new" cable. Two is to only buy a NOS cable when possible, in Chrysler packaging, as some eBay sellers might be selling NewOldReplacementStock items which might be sourced off-shore.
1965 was the first model year C-body to not have transmission push buttons, as that was the first year for "standardized transmission shifting mechanisms", per Federal safety regulations. Therefore, you are dealing with a one-model year only situation, which is why the prices can be higher, no matter what.
Parking brake cables are much more generic and cover many more model years, so their prices are lower.
In general, there are several things on the 1965 models which make that model year a transitionary model year between the 1964 and prior models and the 1966 and later models. Although the 1966 cars look pretty much the same on the outside. So in theory, you could covert your car to 1966 specs in this area. It would take, at least, a 1966 steering column and the full transmission linkage between the bottom of the steering column and the transmission to do that deal. In theory.
So, make your best decision on getting the cable shift items acquired and installed.
Enjoy!
CBODY67