One of the easiest ways to build a collection quickly is to buy a few sets of Pixi books, which come in bundles of eight small softcover picture books (a little under 4”x4”) for less than $20. There are sets that all related to a theme (e.g. the farm, good night, winter, vehicles, Christmas, Easter) as well as reprints of specific series (e.g. Meine Freundin Conni, Ich hab einen Freund, der ist…, Tilda Apfelkern). These are a great value due both to the amount of content you get, but also because they tend to include content that appeals to kids from preschool through elementary.

I recommend buying these new, because they are inexpensive and when buying used the sets often get broken up and sold for more than they are worth. You can find them with this keyword: “Pixi-8er”. Some top recommended sets available on Amazon.com: Leo Lausemaus, Entdecke die Welt, Was ist Was, Conni, Fahrzeuge auf der Baustelle (an all-time favorite that includes three of our favorite books: Riko Retter der Straße, the only German book I am aware of that features a Black father as the main character, the adorable rhyming story Klaus baut ein Haus, and a whimsical Willi baut, about an enterprising beaver who builds a skyscraper for mice).

Carlsen also produces a range of advent calendars filled with Pixi Books. In my experience, the paper the advent calendar books are printed on is slightly thinner than the ones in the sets, but the calendars are a good value for the volume of books you get and the calendars are beautiful and a fun experience as well. Kinderbooks is the best source for these — they have a stunning variety for all ages and they are extremely well priced and offer fast shipping (see selection).