Notetaking with Latex and collapsing text for research papers I am looking for a note-taking software with the following features,
I would appreciate any advice! 


Collapsing or folding text (Like FoldingText or other outliners)
Ability to quickly write up formulas (Like stack exchange's Markdown)
Relatively pretty
Nice writing experience 
Hopefully cheap


This would be helpful while taking notes from research publications side it is highly unwieldy to have a sparse collection of text files.
You could use Emacs/org-mode. Advantage: It is a simple yet powerful (and in principle infitely extendable) plain-text outliner with all the features that you require. Disadvantage: It requires some familiarity with the Emacs-editor, which has a relatively steep learning-curve.