I'm not entirely sure, but the period you're talking about, the bike should have the Benotto 'heart' shaped cut outs in the lugs, normally there are 2 slots cut cross ways in the bb, the stickers definitely don't look like the Italian ones. Anyone can stamp an 'I' in the bottom bracket, are the drop outs marked 'Brev Campagnolo'? Most Italian bikes (Benotto's included) used Campy drop outs on both the front & rear, that being said, other manufacturers around the world used them too. It's still the stickers that make me think it's a South American Benotto. The other thing that worries me is the shape of the rear drop outs, Italian Benotto's normally have the centre of the drop out cut out (see my 2500 & a month or so back there was a piece about a 3000 total resto in the US), see the rear drop outs are 'filleted', the ones on your bike appear to be solid, it could be an anything with some Benotto stickers put on it.
I'm guessing that it's worth maybe $350 tops, would have been worth more if it had a full gruppo of one type or another, but with bits from here bits from there, it losses a certain value.
Early stuff, really needs to be either perfect concours condition or atleast full period (with patina) to be of any real value, then it's market price, my 2500 Chromevelato only cast me just under $300 landed, a 3000 in similar nick would fetch around $400 to $500, but you need someone who either loves old Italian or is a bit of a Benotto fanatic (like me), otherwise the general cyclist has no idea what a Benotto even is, so then you're looking at competing with the $100 to $200 Repco Superlite's & the like.
The 'filleted' Brev Campagnolo used on European bikes around that era (also on my Spanish Razesa).............

The 3000 model recently restored by a US forum member......................

A close up of the detailed lug cut out featured on most steel Benotto's of that era...............

Here's a photo of Giacinto Benotto with a 3000 model in a factory photo, late 70's...................

All in all, I have some grave doubts that your bike is an Italian Benotto, as I said earlier it may not even be a Benotto.
Sorry about that.