I think the best way is to give new players free 500 crafting inventory like old players got, or make it level base for example when they reach some lvl their crafting inventory also increase or get "Crafting Inventory Kit". Remember, new players can't trade before they buy "Trading Permit", so they can't get more gold except from quests. Trading permit need 100 Story Tokens, that mean 10 days playing daily quest from bard. My brother started play 3 days ago, now he already reach lvl 32 and start lvling in Shuyal maps. Shuyal drop primary jewels, but,,, because limited crafting material slots and can't sell the jewels too he just deleted them one by one along with energy essences.

What come in my mind, can new players ( no plat buyer ) buy Crafting Inventory slots if sts make them tradeable ( only ) by purchasing them with platinum?
If they charge too high plat buyers will sell it with high price too, new players only get gold from quest ( remember they can't trade yet ). They also need gold for feeding pets -,-
If they charge too low, will plat buyers buy them then sell them with less profit ?

The best way just give new players free Crafting Inventory