Coming from a player of the PTCGO---
Id definitely say that Dark Explorers is probably the second most valuable pack online next to Plasma Freeze. It contains a multitude of deck staples and 1/3 of the EXs are still very playable. Also contains Pokemon Catcher SR which, while harder to pull, is still much more valuable online and IRL too than FA N.
If I had to rate the pack values of the BW sets in order of most sought after(valuable) to least it would be-
PF
DEX
PS/BC
NVI/NXD/DRE
EP/BW
The reasoning behind placing EP last is, simply put- it contains 4 unique cards that are used right now. Catcher, Goth, Max Potion, and Crushing Hammer. IIRC Crushing Hammer is now in a "Basic" deck which can be unlocked for free, and Catcher is as well. 2 copies of each I think. So the demand for those packs online is much, much lower than others.
Next Destinies, Noble Victories and Dragon's Exalted all contain a FEW cards which are meta staples, and somewhat sought after.
Mewtwo, Prism, DCE, Level Ball, and to a lesser extent Heavy Ball/Sky Arrow are all Next Destinies has going for it.
NVI only has Terrakion, Virizion, Kyurem(Glaciate), Cobalion, and N. DRAGONS EXALTED has ChompTaria (rarely played), Hydreigon (also rarely used now) and the Blends... probably forgetting some stuff.
Most of the decks played online (that I see at least) are made up of the top 4 sets I listed, with a couple of the other cards from other sets spotted here for there.
So if youre going to charge 40 cents for Plasma Freeze, Id say the next step down would be 35 for the other top 3 sets' packs. Just as an example.
