Many of us use mail order shopping from the states (L.L. Bean http://www.llbean.com or Land's End http://www.landsend.com).
There is a factory outlet in Ampfing called Dimor that sells jeans at greatly reduced prices (be prepared for sticker shock: jeans typically cost about 50 here!).
Some clothing shops in Burghausen that you might like include: Modica (on Robert-Koch-Str.) and Mayer (in the AltStadt).
Two recommended shops to check out in Munich are Peter Hahn (natural materials only) and Mühlhäuser.