So I "splurged", which is way too big a word for this, and bought 3 packs of real Bernina bobbins. Using generics is not good for the precision working of the machine, and though the difference between bobbins is tiny, it is truly visible.
So while I was at it, I replaced my seam ripper which has been broken for probably about 4 years now. You can see from this discussion so far that I am a total penny pincher. I admit it.
And now, here comes the actual splurge - though again it's way too big a word. I bought a variety pack of little tweezers. They might come in handy for slipping patches under tears during quilt repair. They might come in handy threading needles in tight places. And besides, don't they look like fun!