Some math on the trade up system. Trading up lead cards to bronze takes 2.5k credits and has a 1 in 9 chance of being the specific loadout you want (assuming you have one optimal loadout that you are looking for). You will spend an average of 22.5k credits if you try to get a specific bronze loadout you want via trading from up from lead.
Alternately, you can spend 17.5k credits and buy the specific loadout you want from the store. You save an average of 5k credits and don’t have to worry about bad rng, but you don’t get a bunch of other shitty bronze loadouts. Overall, one of these options sounds better than the other.
Also, don’t even think about crafting silver+ loadouts from lead. Even silver loadouts cost 12k a pop, and gold loadouts cost 52k if you are starting from lead. Crafting these loadouts from lead is equivalent to throwing credits down the drain. If you have hundreds of thousands of them and nothing to spend them on, have fun. Don’t be surprised if you get nothing of value in return, though.
To be fair, if you have the bronze loadouts sitting around, crafting a new silver is cheaper than crafting a bronze from leads. However, it is still less efficient than just buying your bronze loadout of choice directly (18k average cost vs 17.5k guaranteed cost).
Also, if the trade up odds are fair, there is a 0.17% chance of not getting your desired loadout after crafting 54 random bronze+ loadouts for your desired merc. If a thousand people try to craft 54 random bronze+ loadouts, there is an 82% chance that someone fails to get their loadout of choice. Congrats, you are that lucky someone. Have a t-shirt.