So I received from my sister her Medela Pump in Style breast pump. It is probalby 3 yrs old, as she used it for her two sons. I know that with that pump it is a open system and should only be used by one person. But coming from my sister I feel more comfortable using it than if it was from a stranger. Would you use it (with all new tubing of course) or bite the bullet and by a new one?