I walk by this marked almost every Sunday and once in a blue moon I do find a bargain there. It is…read moresurely best during summer, with far more sellers present. Recently, stands with expensive "designer fleas" have started to sell there. I see no point in paying loads for used stuff. Also, some stands sell new things "made in China". why?
The best deals are done where the boxes full of unorganized things are. You can haggle with the sellers and leave happily with an old treasure. Normally, also a vinyl seller is there with some nice deals. All in all Birkelunden Market is worth checking out, but be patient :)