I would say $150 - $200 for the 162 and $30 for the 71 (depending on conditions and accessories included).
I have always found ebay to be a good indication of asking prices and what something may be selling for. (See bottom of the page link below).
Pro-162 - The RadioReference Wiki
You can also check the classified section here at RR.
A Google search will return results as well - Radio Shack PRO-71 Scanner $30 shipped - RC Groups
I would sell at auction as some vintage radios may bring more that you would expect depending on collector value. I sold a few vintage scanners years ago on ebay for close to or more than their original price.