Nothing Major About Series 80
Series 80 just means it has a passive firing pin safety. Plunger holds firing pin in place until the trigger moves rearward. Designed to prevent discharge should the gun be dropped.
I don't like them, but many people do and carry them with no problems.
Price sounds good, and it could make a great base for a custom build later on.
Good luck with it.
"Certainly there is no hunting like the hunting of man and those who have hunted armed men long enough and liked it, never really care for anything else thereafter." Ernest Hemingway