As it stands, there are 2 inventory-size-increasing accessories in the game:
The Bag and the Satchel.
The Bag gives you +4KG to your carrying weight, but weighs 1KG.
The Satchel gives you +2KG to your carrying weight and also weighs 1KG.
You can not wear both at the same time.
My suggested changes are as follows:
Increase the carrying weight of the Bag to 10KG, and the Satchel to 5KG.
Allow both to be worn at the same time.
Keep their weights in the inventory the same.
That way, there's a reason to actually buy/make/trade for these items and equip them.
For the rest of this suggestion, BCW will mean Base Carrying Weight, the standard inventory size.
BCW = 25KG - 0KG = Net 25KG
BCW + Satchel = 25KG + 5KG - 1KG = Net 29KG.
BCW + Bag = 25KG + 10KG - 1KG = Net 34KG.
BCW + Bag + Satchel = 25KG + 10KG + 5KG - 1KG - 1KG = Net 38KG.
Wearing both would give your inventory a 52% carrying weight increase, making them viable for use and worthwhile to make/buy/trade for.
The Bag and the Satchel.
The Bag gives you +4KG to your carrying weight, but weighs 1KG.
The Satchel gives you +2KG to your carrying weight and also weighs 1KG.
You can not wear both at the same time.
My suggested changes are as follows:
Increase the carrying weight of the Bag to 10KG, and the Satchel to 5KG.
Allow both to be worn at the same time.
Keep their weights in the inventory the same.
That way, there's a reason to actually buy/make/trade for these items and equip them.
For the rest of this suggestion, BCW will mean Base Carrying Weight, the standard inventory size.
BCW = 25KG - 0KG = Net 25KG
BCW + Satchel = 25KG + 5KG - 1KG = Net 29KG.
BCW + Bag = 25KG + 10KG - 1KG = Net 34KG.
BCW + Bag + Satchel = 25KG + 10KG + 5KG - 1KG - 1KG = Net 38KG.
Wearing both would give your inventory a 52% carrying weight increase, making them viable for use and worthwhile to make/buy/trade for.