Running lowering springs on stock dampers is just decreasing the life of the stock dampers. They are designed to be used at stock ride height, so when you lower the car nearly (or more than) 2", you're forcing the dampers to compress constantly to make up for the lower height. This is basically "using" the dampers more than you would have given a stock height. Ride quality is sacrificed and performance-orientated handling is not as good as it could be.
If you can't afford aftermarket dampers, you don't HAVE to get them right away. Like LeeAnn mentioned about my last car, and other people here have stated, you can go quite some time on the stock dampers with a nice drop. Just know that you'll have to replace your dampers sooner than you would have otherwise.
If you can afford the dampers, get them. The ride quality is so much smoother, the car will handle better, and they will last MUCH longer.
