Motivated seller or bad choice?

we are looking to buy our first house and we found a house that has been sitting on the market for six months. On the outside it looks very good just outdated with the painting and the flooring. The house was originally listed for 355,000 and they have dropped it to 340,000. Would it be a bad idea to offer 315,000? What would be a reasonable offer? It is a four bedroom house 2500 ft.². Has a good backyard and it’s in a good neighborhood. However, the location isn’t overly exciting or anything. Just an average good area of town. Any feedback would be helpful!