I have been taking notes on my iPad since the iPad1, and am a bit of a stylus geek - always looking for something better. I have more styli in my home than regular pens, since I never use paper any more.
In terms of cheaper ones, I found these
iHome ones at Marshalls and TJ Maxx, usually they cost $10 there, but I found some on sale for $5. They are woderful, and if you ever want to also write with them, they are great for that as well. The tip is among the smallest.
There is also the Adonit Jot stylus, which has a very fine tip and a cLear plastic circle around it - I have it, but it's not my favorite, and it's a bit overkill for what you are looking for.