Don't buy anything from a dealership.  You will be sorry.

the usual problems for 34 year old cars.

• gas hog (gas was less that $1/gal back then)
• aging plastic/rubber
• fatigued metal
• require more frequent maintenance
• might become a "project"
• slow

don't use it as a primary driver, and don't pay too much.

on the other hand if you can get it for a few hundred bucks to use a weekend car, it has plusses:

- fuel injection. great for cold mornings.

- front wheel drive. Better traction/handling, and easier to drive in severe winters.

- reliable engine.

Another kill joy answer!

A 1987 Oldsmobile? 

Being sold at a dealership?

I would pass on that alone. Unless you want a weekend project and for some reason have fallen in love with the car. But as a daily driver? Absolutely no way I'd recommend it. Mileage isn't everything. I buy a lot of classic cars and some had very low miles but I had to replace a ton of parts due to age to even make them road worthy. 

Save your money for something newer.