In particular, I would point to the seller "D-Edition de": very very low price. Shipping via DHL package. It was in connection with the DHL shipping an annoying problem. This problem was solved by the seller "D-Edition de" professionally very quickly and to my complete satisfaction. The reaction of "D-Edition de" in my e-mail to the problem was also very fast. My full respect.
A tip to Fischertechnik Boxes: Look at the Fischertechnik packaging carefully. There you can see, with which parts you can add to the box makes sense (here: Motor Set XM, Accu Set, Sound + Lights, Control Set), or which parts of the operation provided additionally needed are (nothing here but some robot Box sets a Fischertechnik computer plus software plus power forward), for example. And finally: Some boxes include, for example: already a good power supply or other parts.
Have Fun
Thomas R.