A ningún tonto lo amarga un dulce

[ROBINDESBOIS]

We use this stock phrase to mean that anything free is welcome.
Do you have a saying like that in English?
It can be used in any context.
A dinner invitation
a free ticket to whatever
a free fligth to whereever
a free ride with a beautiful whomever
etc....:butterfly:

[AngelicaDeAlquezar]

In Mexico one can say "Gratis, hasta las puñaladas" (if it's free, one can even take a stab) o "A quién le dan pan, que llore" (who would cry if given bread). The second one is more general to a situation in which a person is offered a good thing or a good opportunity without having asked for it.

[Rusty]

"You don't have to twist my arm," is what I've heard said.