How to spend your orichalcum effectively?

Hello to everyone who passes by. Well I've already finished the game and the DLC (several times thanks to ng+), I have something like 600 skill points, I have all the non-generic legendary and epic weapons and armor, a monstrous build in terms of damage and the last thing left for me to do is to loot the helix store, but I refuse to pay any real money.

Fortunately, there is Sargon and his shop with random loot and the orichalcum quests (which brings in around 100 of these blue stones per week). I know that his shop resets every week and each time offers 2 legendary items (and 2 epic but I don't care) each costing between 60 and 100 Orichalcums (but if I buy everything that is offered each week I will quickly be in deficit). But the store also offers a random gift for 20 orichalques as long as you have the money to pay. These gifts can be epic or legendary but I have no idea how often legendary loot appears).

My question is: is it more profitable to pay Sargon for one of the legendary items from his shop per week or to take 5 Olympic gifts each week (I think that's what the game calls them) in order to not spend more Orichalcum than I get per week (and thus keep my reserve in case the 2 items of the week really appeal to me) and to get as many items from the shop as quickly as possible (although I am aware that this will take month anyway)?

Thanks to everyone who took the time to respond to me!