A 35-year-old car, because the 1985 model was actually built in 1984, with 149K miles on it isn't going to be reliable. It might be a great project car, a hobby car that you can tinker with and fix up, but to get you from A to B on a day-to-day basis, you should look elsewhere and spend that $1,500 on something else.
I mean, do you have any idea how expensive it will be to repair a 35-year-old BMW? BMWs are massively expensive to fix, and a 35-year-old one is going to be even more massively expensive, and that's if you or your mechanic can even find the parts you need, which will in all likelihood involve going to junk yards and trying to find an unbroken or unworn part on another one that's been junked.
Also, in the 70's and 80's, cars were only good for about 100,000 miles. Cars were almost always junked by 150,000 miles. Technology has come a long, long way since then such that we now see cars doing 250,000 and 350,000 miles on their first engine and transmission and without needing a complete overhaul. So, a 1985 BMW with a 149,000 miles on it, even if it weren't 2019 and 35 years old, it would be maxed out on miles, on its last wheel, as it were. Say it's not 2019 right now. Say it's 1994. In 1994, there's no way in hell I would have paid $1,500 for a Bimmer with 149,000 miles, not even a 735i.
owned a 1991 BMW 325xi and a 1974 BMW 2002tii