I was there when the DM was converted. Didn't see that much change except for tipping, which previously was typically rounding up the pfennigs (change) up to the next higher DM, changing to the next higher €. Also prices of the the cheapest ice cream cone went up from 1 DM to 1 €. Both cases amounting to a 100% increase.

As far as bicycles and accessories, I didn't see significant changes in price by Euro as of 2002. In fact I bought two commuter beauties for my daughters in Euro at the local Opel dealer who also had a small LBS within. A 3 speed Calvin (built in Germany by Biria) fully equipped as a commuter with Sachs Torpedo 3 speed IGH Coaster brake, Nokian 622-47 tires, etc., etc. Cost 365 € which was about $320 at the currency exchange rate back then. Bought a ZeroSeven Express for about 500€ (about $460) equipped with Sachs 7 speed IGH with coaster brake, balloon tires 26" x 2.125" and the normal commuting equipment. Of course bikes were completely assembled and ready to ride when we rode them home from the dealer, about 1KM. Never needed any adjustments by the seller.