just start selling yourself SE

[Vahlnir]

Since being among the first to clear certain content is considered a big deal by the softcore.. I mean hardcore crowd then yeah that would be an endgame advantage.

Time isn't the reward, at least not in the context of the OP. They are talking about selling endgame rewards for real money. Jump potions only provide a skip to lvl 70 (currently), which isn't even max level. They still need to grind to get there. So no, they don't provide much of an advantage when it comes to getting endgame gear from raids. You can only get so far.