You're right on target; proof year 1982. Barrel weight is a little on the light side for much use of 3 inch shells, but the stock looks like it could take it.
Gun appears to have been made for some American retailer.
Armas Ego, like almost all the Spanish artisanal shotgun makers, made guns to every price point at which a demand existed. Your gun appears to be a mid price point gun (roughly like an AyA model 117). Ego did some very fine work, and even produced some top notch double express rifles.
Value, in the sense of what the gun might bring if sold today, is hard to tell. Armas Ego is not a well known name, and most people buy the name rather than the gun. I'd guess (emphasis on "guess") it would bring a minimum of $1200 USD and could go for twice that.
Hope this helps.
