If a component sells for more than 750 gils and it is not one of those high EXP components, you should sell it. The only components you need are the a few EXP components and a few multiplier components (all of which you can buy). They rest are for cash or are useless fillers added to clutter the component list and feel like you got something for beating most of the enemies.
"some components boost the multiplier quicker, chocobo tail feather is one I believe.. but not dawnlight dew."
The only multiplier components I used (other than using the worthless ones just to declutter the inventory list) were Sturdy Bones, Vibrant Ooze, and Barbed Tail. They cost only 80 gils and you only needed 36 to max out the multiplier. What was the point of having 200 different multipliers or 200 different EXP components when most of those were just crap (50 EXP points? Why even have it in the game?). It would have been nice if the different components added different abilities (like FFX) or they had fewer components with each enemy dropping just the useful ones.