As others have said, they are great for analog systems. Those prices given are also for ones not modified per the popular manual for that receiver.
If the Pro-2006 has an Optoelectronics computer control board in it, it may be worth more.
Being in an area with a lot of analog in use, my Pro-2006 is still used often. This is one of the best radios for analog systems that was ever made.
Even with no analog services, FM 88-108 MHz radio comes in well with these too. Could be a nice conversation piece radio for local stations. Mono speaker output is not the greatest though for music.