I’ve let my thoughts and experiences simmer for a few days on this instead of throwing out a “hot take” on my feelings about the matter.
So, I’ll start by prefacing one of the very last (if not the last) mechanics/design philosophy posts by Sirrian, where he describes the theories surrounding Tier costs on the eve of the launch of Raid Mode.
Four months later, with hindsight being 20-20, there was a lot of information to be gleaned from this post that the playerbase did not know to look for at the time.
From his post, the intention was a minimum of Tier 4 to clear an event, but with the disclaimer that while mathematically possible, Tier 5 was needed for a realistic full clear.
Tier 4 = 30 + 70 + 150 + 250 = 500 gems (mathematically possible minimum clear cost)
Tier 5 = 30 + 70 + 150 + 250 + 350 = 850 gems (realistic minimum clear cost)
As the Class Events are solo experiences, for the sake of the analysis, the fact that entire guilds need to buy in at those level to full clear an Raid Mode / Invasions is irrelevant here.
Next, a comparison to the costs of the Class Event is necessary. From higher up in the thread, @Slypenslyde provided the relevant costs and rewards.
What’s relevant here is the reward for the event, class XP. After all, it’s the point of playing the event (outside of newbie players who don’t have the class unlocked and want to just buy the weapon/traits outright). Examining the class XP gains in terms gems costs from shop purchases is quite revealing:
Tier 1 - 5 XP - 30 gems
Tier 2 - 20 XP - 100 gems
Tier 3 - 70 XP - 250 gems
Tier 4 - 220 XP - 500 gems
Tier 5 - 470 XP - 850 gems
Tier 6 - 830 XP - 1350 gems
Tier 7 - 1330 XP - 1850 gems
Using Sirrian’s logic, Tier 4 would be the minimum expected spend to make the event “worth it”, at 500 gems. Note how the total purchased XP at Tier 4 its more than triple than stopping at Tier 3 and doubles again for Tier 4. 220 Class XP is okay at very low champion levels, but is very underwhelming at higher champion levels. To that extent, Tier 5 is the realistic minimum to make the event feel worthwhile.
Therefore, the event costs are coded to be in-line with expected gem sink costs for Raid Mode/Invasion/Bounty modes, and is working “as designed”.
So, from the devs’ perspective, the event is mechanically functioning correctly. From the players’ perspective, at least the ones here on the forums, I personally agree that the buy-in costs are too high (at least for a 1-day only event; even pets only have a 175 gem minimum buy-in to guarantee the pet). On the other hand, I’m reasonably confident that the players on this forum are NOT the target audience for this event. The devs know that we are willing to grind out champion levels, and to that extent, they are likely okay with this. The event is designed to target new players, by offering them paid shortcuts to minimize the grind and to fast-track champion levels and talents, class traits, and the relevant class weapon, that we all grinded for on the way to end-game.
From the brief examination of the leaderboard for the event, I’d fathom a comfortable assertion that the devs likely considered the event on Thursday to be successful.