I've got the perfect solution for you. Stop buying your media on spindles...order the stuff that comes in tape wrap instead. You unwrap the blanks and put them on your old spindle. I've got two 100-capacity cake boxes that originally came with some Taiyos and I just reuse them (one for blank CDs, one for DVDs). As long as you don't open the tape wrap, it is perfectly fine to store the discs that way if you're out of empty spindles to put them in.

I'm certain there are other solutions besides reusing them, but I'll leave them to the imagination. Worst comes to worst, maybe you can recycle them.