I don't buy any energy at the moment for a very simple reason:
its just energy!

What I would like is this: tons of choices of Energy packs, all containing different extra items (could have similar/same prices). Yeah, I want free items! But not for free items themselves, I just like the idea of having freebies when paying dollars.

For example, add some few crafting orbs to $2.50 or $5 purchases. Add some fire crystals. Add heat amplifiers (those don't have much point now, so why not?). Make it all bound to knight if you're afraid it will "crash the market". As I see it, Energy market has already crashed (its over 8.4, which means energy will soon disappear into private trades over 9999 crowns per 100 energy).

The only way to make energy price go down is to make it so players have lots of energy on their hands and there are numerous things to buy for crowns, not energy, and paying lots of crowns for it. And the only way to make it so lots of people have lots of energy is to give people a very good reason to start spending $$!

For example: $1 energy packages, $2 energy packages, $3... ect. Some could even contain packs of minerals, others would give unique costumes (BOUND), some would give much-needed items, like orbs of alchemy ect.
It should all contain energy and not just items for a very simple reason: if people buy pack for items inside, they end up having excess energy, which, with enough crown sinks, will be converted into crowns, thus lowering price of energy down to more reasonable levels.

Summarizing it all:
we need energy packages that contain desired items, and not just energy. As long as people purchase item packs with energy as a bonus, they'll have more energy than they can spend, and having a reason to spend it (on crowns) would make energy exchange rate drop. This, in turn, will make it easier for free-2-play knights to progress through the game and, eventually, possibly, start purchasing energy packs. My naive opinion here.