O exemplo 1 contém a leitura correta desta regra.
Como apontado por Ernir, o Magic Item Compendium contém regras atualizadas e esclarecimentos para a criação de itens mágicos.
O número da página 233 do Compendium Item Mágico aborda este caso e declara que:
In most cases, if the item is one that occupies a body slot, the cost of adding any additional ability to that item is 1-1/2 times the value of the added power (or the value of the added power plus 1/2 the value of the existing item, if the added power normally costs more than the existing item). For example, if a character adds the power to confer feather fall to her ring of jumping, the cost of adding this ability is 3,300 gp, the same as for creating a ring of feather falling × 1-1/2. On the other hand, if she were adding the power of a ring of force shield to that ring of jumping, the cost of adding the ability would be 9,750 gp (8,500 gp for the ring of force shield plus half of 2,500 gp, the price of a ring of jumping).
Também é importante notar que o Compêndio de Itens Mágicos atualiza o custo de Múltiplas Habilidades Diferentes para ser 1,5x ao invés de 2x.