In the salvage yards in Germany, these lights go for about DM180 each. Last summer, the exchange rate was about DM2.40 to the dollar making them about $75 each. This is the best I remember. I haven't checked the exchange rate lately.
I thought I was going to Stuttgart last April, but my meeting ended up being in Switzerland. I have a European meeting coming up again the end of September and hope it is in Germany so I can get another chance at an affordable pair of Euro lights.
I believe that to customs this stuff is pretty much junk, and might be purchased from a German salvage yard and shipped here pretty inexpensively, although I haven't tried this approach.
If you upgrade to Euro lights, there's really no need to add more powerful bulbs and the necessary associated wiring. The integrity of a light is almost entirely in the reflector. The MB 124 light reflectors for the US market are junk, but the Euro's are top notch, alleviating the need for more powerful bulbs. The heat they generate, damages the internal wiring of the headlight assemblies. I have a set on my 240D that I got after someone used 100Watt bulbs. They have a distinct burnt electrical smell and the connectors are brittle. I suggest that you stay with Euro reflectors and standard bulbs.
Have a nice day,