this etsy seller. I love it is big enough so I can ply the 100 gramms or so without having to break the yarn.
100 grams of shetland wool, about 700 meters of two ply.
As for answering some questions...
What fibers I like to spin with? Up to now my favourites to spin are the ones mixed with silk, Merino/silk, BFL/silk is my favourites. I have spin pure merino, and pure BFL, I didn't think spinning BFL was that much easier... No, it definetly didn't spin itself. This shetland is a bit to "rough" to my taste. Currently I am spinning some plain cream colored alpacca, and though it is silky, it is... just a bit too much to handle. Back in the beginning I had the luck to try a tiny bit of quivit, which wasn't as difficult as I thought it would be. Now I have some yak and silk, and camel and silk coming in the mail, I can't wait to try them.
Is spinning hard? To tell you the truth I don't know... Maybe it is in my genes, with a little practice it came pretty naturally to me. I don't think it is harder than knitting for that matter. It does need practice, and I found the ten minutes a day practice does have good effect.
Why do you spin with spindles rather than a spinning wheel? Though I did acquired two old spinning wheel (one of them is in working condition), I still prefer the spindle. I like the fact that I can just stuff it in my bag (or pocket) and the controll it gives me... or maybe I just didn't had enough practice with the wheels.
Do you use really need different spindles for different jobs? I've red at Abby's blog that it is not necessary, Andean spinners can spin almost anything with their spindle, I found it IS easier to spin fine yarns with a lighter spindle, medium yarns with medium wight spindles. And I found the big star shaped plying spindle most helpful.
Do you do your plying with a spindle too? Yes. Though I did plied some thing single on my wheel, but that was a commercial yarn. Plying with the wheel is definetly faster, but my wheel is old, the flyer is not smooth enough.
Is spinning your yarn cheaper than buying it? NO. Good fiber cost just as much as good yarn. Add to it the time one spends with it... NO I don't do it because it is cheaper or faster. (But after knitting it is nothing new).
Why do you spin then? Because knitting is not weird enough. (That is my standard answer). Seriously? I think it is in my blod. It fascinates me to no end to do something from scratch (that is why I bake bread too). Because when I spin something, even if I knit a pattern hundreds or thousands knit before I will have a totally unique result.