WTB: Rear springs broken 2001 330xi

For the past month there have been some rattling noise coming from the rear suspension area and today,as I was driving down to my parents house(who have a garage) to take a look at the problem, I heard a metallic piece falling onto the asphalt behind me. Luckily I was able to stop and pick it up - it was top part of the rear spring.

When I finally took the tires off to inspect it, I also discovered that the left spring is broken as well. I looked around the forum and this seems to be like a typical issue for a 100k BMW.

So I have few questions:

1) Can I still drive my car or should I let it rest until I replace the springs.
2) I'm looking to get an OEM replacement as I don't want to drop my car or affect change the stiffness of the ride. Tischer has them for $135 each - is that a good price?

Or maybe someone has their old springs still laying around - that would be even greater. Please name your price and shipping unless your are in Boston area.

Thanks!