My first thought is why in the world would you buy a left hand bow if you're right handed. And if it was given to you who cares what it's worth. Get what you can for it and get a right handed bow. As for shooting a LH bow RH it has to be very uncomfortable in the hand. And how do you contort your head for the sights?
I wouldn't worry too much about eye dominance. I am left eye dominant and shoot a bow RH. Why? Because that's how I was taught about 55 years ago with a recurve. I can shoot 3-5" groups using my non-dominant eye at 70 yards during practice sessions. I toyed with the idea of shooting LH because you can get some real deals on LH bows. But I am too comfortable with my muscle memory shooting RH. It seems unnatural shooting LH.