Troy-Bilt 8000 watt 13500 starting watts 15 horsepower

I have only used this generator 3 or 4 times when my friends that has a food truck generator went out and he had to leave his at the shop for a week. But other then that it was unopened in its original box for 2 or 3 years. It has a 15 horsepower engine and electric start but it is actually very easy to pull start too. It was sitting in its original box and the battery has run down from just sitting but It starts on the first pull every time. And I'm sure it just needs a battery charger connected to it. But I will tell you exactly what I paid for it at $1200 before tax and I am going just looking to get $850 out of it