In the DMG for D&D 3.5 on page 285 there is a chart for estimating the cost of new magic items. Under the section "Special" there is an attribute titled "Multiple Different Abilities". This attribute reads "Multiple higher item cost by 2".
Does that mean that you add the highest effect cost to the price again, or add double the highest effect cost to the price?
The following two examples may explain it better than I:
Ability A: 1,000gp Ability B: 3,000gp Ability C: 5,000gp Multiple Effect Cost: 5,000gp Total: 14,000gp
In this example the cost of Ability C (the highest costing ability) is effectively multiplied by two by adding its cost again into the calculation.
Ability A: 1,000gp Ability B: 3,000gp Ability C: 5,000gp Multiple Effect Cost: 10,000gp Total: 19,000gp
In this example the cost of Ability C (the highest costing ability) is multiplied by two and added back into the cost.
The calculation comes out very differently depending on how you read that table line. I tried to reverse engineer a few items from the DMG, but failed to do so properly. Does anyone know how the rule should be read?