Read this Borderlands 3 guide on how to increase inventory space by buying SDUs (Storage Deck Upgrades)! Including info on how to unlock SDUs and which one to buy.
Increase Inventory Space With SDUs
You need to buy SDUs (Storage Deck Upgrades) to increase your carrying capacity. However, you need to buy the corresponding SDU for each inventory or ammo type. For example, if you want to increase your pistol ammo capacity, you need to buy a Pistol SDU.
|Assault Rifle SDU||140|
|Sniper Rifle SDU||12|
|Heavy Weapons SDU||3|
|Lost Loot SDU||1|
SDUs Cost A Fortune
SDUs have an initial cost of $1000. Buying one triples the next SDU's cost ($1,000 → $3,000 → $9,000 → $27,000 etc.). With this system, it is highly recommended to prioritize buying SDUs for weapons that you normally use.
You Cannot Buy Weapon Slots
Weapon Slots cannot be bought from Marcus. Each one is unlocked as you complete missions in the main story line.Learn How To Unlock Weapon Slots Here!
Which SDU Should You Buy
Prioritize Backpack SDU
Backpack SDUs increase your item carrying capacity, allowing you to pick up more weapons and mods. It is highly recommended to prioritize this SDU as it gives you more room for loot to buy upgrades. The more loot you get, the more you can sell, and the more you sell, the more cash you have to buy your ammo SDUs.
Buy SDUs For Assault Rifles & SMGs
Assault Rifles and SMGs in Borderlands 3 burn through ammo like there's no tomorrow. As you'd likely run out of bullets when fighting against tough enemies and bosses, it is recommended to increase the ammo capacity of these weapons as soon as you can.
Weapon Ammo Is Shared Per Type!
Note that each weapon type takes ammo from that type's ammo pool. Efficiently use your ammo by diversifying and carrying different weapon types.
Buy Grenade SDUs For More Boom!
Increasing grenade capacity is a must as you need to have more splash damage against enemy swarms and bosses in the mid to latter parts of the game.Click Here For Legendary Grenade Mods!
How To Unlock SDUs
Help Marcus In "Sanctuary"
The story mission, "Sanctuary", tasks you to go around Sanctuary III to meet characters while familiarizing yourself with the place. One of the characters that tag along for the ride is Marcus, the gun dealer. Help Marcus in the dousing the flames to unlock SDUs.Click Here For The Full Sanctuary - Story Mission Walkthrough!