"Anything for You" joke

Heard at a rock concert at La Trobe University,
Melbourne Australia.
I had a major argument with my girlfriend, Helen. I was in the wrong,
but not enough to back down without an argument.
So after storming away, and cooling off, I had a think. I was
clearly in the wrong and felt pretty guilty, with all the trauma
it had caused.
So to make it up to Helen, I said I'd buy her a gift.
"Any thing at all, my love," I said, overcome with remorse.
"Oh, I don't know," replied Helen,"You really shouldn't do
this you know. But, if you are, just get me something
really expensive, that I don't need."
The following day I booked her in for chemotherapy.