I had a look at the flea market there -- books they were selling off at prices from €0.20 to €1.00. I got an "encyclopædia of Asterix, L-Z" for €0.50 and book 2 of Mafalda for another €0.50.
I'd heard about Mafalda from Mark Rosenfelder and Bob's Comics Reviews (for example, the series is described as "the Latin American Peanuts"), and so it was double interesting to pick it up.
After flicking through a couple of pages, it seemed interesting, and rather deep at times. Take this joke, for example:
"I know a good joke!" -- "Go ahead, tell!" -- "A submarine dived and it sank so low, so incredibly low, that the fishes asked themselves: 'Is that a submarine or the exchange rate?' Ha! Ha! Ha! Ha!" -- (silence) -- "Well, it's very deep."