No quieres caldo, toma taza y media

[ROBINDESBOIS]

When you don´t want something, and you have double of that thing. Used in a figuritative context, not in a food context.
English?

[poli]

I have heard this often, said differently.
Así es como lo oigo: el que no quiere caldo recibe dos tazas.

There is no English equivalent.
The closest is: He needs it like a hole in the head, but it lacks the ironic wisdom.

this is how is can be used in a sentence:
Look, Bob won the lottery, and he's a millionaire. Meanwhile I can't pay my
bills. He needs that money like a hole in the head.

[hermit]

Yes, and in the sense of misfortune, "It never rains; it pours.".

[ROBINDESBOIS]

That one is good.