richardvador the 1880 is a common date eagle. It is priced fairly at 5-10% above bullion, around $650-700 US currently.
Weight is the simplest first test for authenticity. I was recently fooled by a counterfeit eagle which I bought from a trusted dealer. I weighed it when I got home and it was 1 gram underweight. The dealer refunded my money. Does your dealer offer that?
"Two minutes ago I would have sold my chances for a tired dime." Fred Astaire