Yes, I bought it from eBay. Here is the vendor that i got it from:
Billiard Pool Ball Shifter Shift Knob - eBayYou have to specify what number pool ball that you want and that you need it threaded 10mm x 1.25 for a Mazda MX-5.
Dab of lock tight and no more rattling shift knob, plus if someone were to steal it you aren't out the $120 that I was quoted to replace the original.