It is just a kiosk where you can get some bottled or canned drinks, newspapers and the like but above all it sells all kinds of souvenirs from Wolf's Lair, some really weird like the plastic death's heads in Nazi helmets (no, thanks, not for us). And anyway, I didn't really want a souvenir from there - I'd rather forget what I had seen.
Yet, they also sell books and guidebooks and we actually used one of them to guide us around the site. We wanted to do the sightseeing at our own pace so the materials came in really handy, although I admit we did eavesdrop when a human guide was giving talks to tourist groups. And of course it was something to take home so that I could write about Gierloz without consulting any other sources.
What to buy: Guidebooks and other publications. Choose a guidebook that has a map of the site with the various places marked with numbers, which will later help you identify them.
We found this gallery and shop selling folk handicraft very interesting. It sells Mazurian and Warmian (Warmia is a land adjoining Mazury from the west) folk crafts and is run by professional ethnographers who can demonstrate some of the traditional skills, like weaving for instance. The traditional crafts of the region include lace-making, woodcarving, amber jewellery making, embroidery, basket weaving and many more. You will also find displayed the national dress of Mazury and Warmia. It is a lovely shop with very helpful and knowledgeable staff.
What to buy: Whatever you like. I loved lots of things there. Some of the items are unique to the area and not to be found elsewhere.
What to pay: The prices are lower than in city shops. Take advantage of the bargains and get gifts for your friends here!