Is it worth for buying legendary crest to get sellable gems?

Game Belong:Diablo Immortal Author:

Most customers initially resist buying legendary crest to get sellable gems, think it's not worth, but this is the game setting, and no one can change this. Our service is to allow customers to get the most cost-effective return from it.

Let's simply do the math, if you buy 10 legendary crests, it costs 1600 Orbs, valued at $22. With these 10 legendary crests, I calculated according to the worst luck, expected to get 1-2 star normal gems, I will count five 1-stars and five 2-stars.

5 * 2000 Platinum = 10000 Platinum
5 * 8000 Platinum = 40000 Platinum

Note: 1-star gem generally can be sold at a maximum of 2000 platinum, 2-star is about 8000. Of course, you cannot sell it directly at the market with this price, this price is sold to us. 

These gems can be sold for a total of 50000 Platinum, minus the 15% market fee, you can get about 50000 * 0.85 = 42500, (42500 / 72000) * $99.99, valued at $59.

Since we bear the value of gems (50% of it's max price), if you want us to buy these gems, you need to place an order on our website for 50000/2 = 25000, which is estimated to be $18 after using the coupon code.

Now you spend $22 for legendary crests, plus $18 on our website for platinum, $40 in total, then you get $59 worth of Platinum, is it a better deal than buying directly from the official in-game store? And it's still based on the worst luck, if you're lucky to get a rare gem or two, that would be more cost effective.

In addition, when you have enough diablo immortal platinum, you don't need to buy legendary crest anymore, you can go to the market to buy sellable gems at a low price, and then sell them to us at the max price to earn the difference, the only downside to this method is that gems have a 7-day cooldown period, which requires patience.