Just Google Munich computer stores.
Just curious. Why would you want to buy computer parts in Germany. ASUS ENGTX560 TI DCII/2DI/1GD5 GeForce GTX 560 Ti (Fermi) 1GB 256-bit GDDR5 PCI Express 2.0 x16 HDCP Ready SLI Support Video Card $225USD on Newegg after rebate.
Same card at a computer shop in Munich, 203 Euros ($276USD)
Then there is that pesky VAT tax they have, 19%. I know this is hardly an exhaustive search but just heads up.