Costume shops

Costume shops sell fancy-dress clothing for wear during Fasching or Halloween.

Halloween Gore Store - a Halloween costume store in Sendlinger Tor area.
Hera Rauch - costume shop
Kostüm Rainer Stegemann - high end theatre quality

All the big department stores have sections devoted to Fasching costumes, but this is seasonal:

Galeria Kaufhof
Karstadt
Müller
Wal-Mart

And Aldi have been known to sell very cheap wigs. But there's no predicting which particular branches and when they will have stock in.

C&A and Woolworth's are both really cheap too.

If you've got an imagination, Kleidermarkt im Tal have lots of second-hand clothing that can easily be made into cheap costumes.

See also the related TT chat topic: Halloween costume shops

Shopping

Munich