Oh for the love of Notch! Guys, this is a TE item, not a GT item, it's not going to be explicitly designed to be completely useless.
Loosing items, ANY of them, just means they will never be used. Ever. Losing energy works, because it is renewable. Plenty of items you try and transport? Aren't.
Sheesh.
Costing more? Delays the inevitable. That's a minor tweak. Costing enderpearls as an energy source? Means it won't be able to be used until after you take down the EnderDragon. Granted, that's not a particularly difficult task in and of itself, but it DOES mean finding a stronghold, finishing the end portal, then going there and doing it. That's not exactly something doable early-game, or even mid-game. It's tedious and a boring grind, to be honest, which is why I generally don't even bother. I know I'd probably never use them if they required a constant supply of enderpearls. It's just too much hassle to set up an EnderFarm to be worth the trouble, I'd just stick to EnderChests, which have a flat static enderpearl cost.