Does that include all the components, speakers and wire for $250? If so that is a very good price, even if you don't want to use the system you could resell it for a profit.
Used ones on ebay are starting at $799 plus shipping.
Speakers don't have a lifespan. They can last many, many years as long as you take care of them. I've got a pair of JBL bookshelf speakers that I purchased in 1985 and are still in great condition. My friend uses them in his stereo now.
I recently purchase some Energy 2.1e speakers that are a dozen years old or more.