I can't imagine that there are many bike components made in Germany that will be significantly lower to purchase in Germany than the price for the same thing from a distributor in the US. The US dollar has lost so much value vs the Euro, it might even cost more in Germany. The reason is sometimes a distributor might have purchased the item when the exchange rate was more favorable to the dollar. Getting your sales tax refunded is just one more little hassle to take care of when leaving Germany, then declare the items for US Customs. It's just not worth it for maybe 10-15 percent savings.