How do you compare the rarity/cost of fodder?

I think we can all agree in general on this order, from rarest to most common:
1. Available only on summonable (i.e. non-TT) seasonal or someone like Saber who basically never shows up
2. Available only on permanent pool 5*
3. Available mainly from TT/GHB unit (ex: spd/res bond)
4. Available from 4*-5* pool (ex: L&D3)
5. Available from 3*-4* pool

But what about something like close def, which is available from a TT unit who offers a skill that's otherwise extremely hard to get because Alm is rare as a focus unit and also available from a 5* exclusive who appears often?

What about something like infantry pulse, which some of us will want a lot of and which is available from two non-seasonal 5*s as well as from a TT unit?

What about something like live to serve, which is 4* available from a TT unit who also yields spd/def bond for 20k feathers or 5* available from a summonable unit?

What about panic ploy, which is 4* available from a GHB unit who also offers distant def for 20k feathers, 5* available from a different GHB unit with little other fodder for 20k feathers, and also summonable from the 5* pool?

How do you make decisions on who gets foddered for what?