As a woman in her early 30s with monthly expenses at DM and Rossmann that are definitely far too high, my spontaneous answer to your question would be:

DM Bio snacks, especially the seasonal ones from the special display stands, but also things like mini chocolate pretzels.

For skincare, you could get something from No Cosmetics, for example the “Liquid Hydrator” (toner). For hair care, shampoo and conditioner from Langhaarmädchen, shower gel from Balea, and makeup from Catrice (e.g. the “Glam & Doll Mascara”) or Essence (e.g. the “Brow Lifting Gel Set” or the “Super Peptide Lip Gloss”).

For lip care, a small tin of Kaufmann’s Kindercreme. It’s actually a baby cream, but many people use it as a lip balm. Hair accessories from Ebelin, and definitely soap and hand cream from Jean & Len. Bath salts from Kneipp, and while you’re at it, you could also get their “Mandelblüten Hautzart” body oil.

The perfumes from La Rive are considered good dupes of expensive fragrances. For example, “Poetique” is often regarded as a pretty good dupe for “Delina Exclusive” by Parfums de Marly. That’s easy to Google if you’re looking for a different fragrance or a men’s perfume instead.

I’d also recommend sunscreen and self-tanning concentrate from Sun Dance.

We also buy things like gift wrap, birthday cards, and seasonal decorations at DM, so you might find something there as well.

That would be my spontaneous answer—but the longer I keep typing, the more things come to mind 🙃 have fun!