Yes, there are also in Portugal (but frequently they don’t work, in my experience at least). But the stamps are even worse than self-adhesive ones (normally here we have some series of gum stamps turned into self-adhesive). In vending machines there are just adhesive labels (with some design) and the machine prints the cost in it.
Like this (it says: Give Blood):
that €0,53 can be any other ‘‘normal’’ value, but it’s printed in that moment (and sometimes not very well…)