I personally thing a main question when purchasing something (unless you are a millionaire) is: “What do I need to do to get this thing otherwise?”
This is why a lot of people are investing into Deathknight armor. Some also buy the avatar looks. These items cannot be gotten by any other means in the game, so the decision to spend money on them is much easier since I’m getting exclusive content.
If it needs a lot to get an item without money, it is also a desireable purchase. Examples of that are the Sunday soulforge pack (lots of diamonds) or, to some, the pack where you get a mythic at the end of it, even if it’s a random mythic. But for me, who was over level 1000 before getting my first mythic, this was a huge incentive.
Things that are not desireable purchases are where things that you can more easily get cost a lot of money. That’s the case for the weekly troop pack (50 bucks for a legendary and some keys?!) and also pure currencies (gems, in conversion in the shop then gold and souls).
The new troops and weapons (tier shop) might be worth it to some; to me only maybe the weapon would be worth it since the troops will be in the chests sooner or later. However, to make full use of spending money (if I would need to spend it on gems to purchase tier things), you would also have to actually play the event and not just does that take a long time, but it’s also hardly a guaranteed thing, depending on what troops you have available and how far you are in the game.
Generally, spending money on games is for bypassing long times of grinding or having to hope for luck. In case of sigils, you basically spend gems/money to be allowed to grind for random orbs. I don’t want to buy the permission to do a chore. To others, who enjoy these game modes, they purchase the entry tickets to be allowed to enter it. That’s totally different then. But because no one knows just how much a (newer, non-endgame) player needs to fully clear sigil events, I find it difficult to say that event X is a good gem-to-orb converter or to price orbs in general.
I personally would buy orbs from the shop because I would get an item which would otherwise need me to grind an unpleasant game mode. I do not buy sigils because they would “force” me to play that game mode (or have essentially wasted my money).
Overall, I feel GoW is odd with its shop. It offers a few good deals like the exclusive content or the pack with a few gems every day. And then there’s horribly overpriced stuff that can be gotten in a few minutes ingame, even for newer players. The stuff that people would likely spend money on, though, because it’s hard to get otherwise, is only available in limited quantities (soulforge bundles can only be bought once a day) or not at all (orbs).
So yeah, I just find the whole shop thing super-odd in GoW and not very thought out. I feel like the devs could make way more money. Quite frankly, I’ve rarely seen such bad buying “incentives” in any game before for 90% of a premium currency shop. 
