I know. I got my T430 from there (without Windows) and bought several Latitudes for friends also from this or similar shops (with Windows, but it was optional).

There are at least half a dozen similar shops in Germany and the quality of the devices and the service is usually excellent.
The problem is, that they have a very limited variety of devices because they resell mainly returned laptops from leasing programs of big companies.
So for the most part you can only buy there what someone else has leased before.
If your requirements match exactly that pattern or if you don't have clear requirements at all, these shops are great places. But if you have clear requirements that can not be met by these few devices (e.g. wicket), then you still have the problem of bundled systems.

Another problem, at least with Lapstore is, that you can only get older laptops without Windows. As a rule of thumb: If a Laptop is pre-configured with Win7 you can usually remove it completely. But if a Laptop is pre-configured with Win8 you can only downgrade it to Win7.


btw:
My post you quoted was about returning Windows licenses. This is a completely different story than buying devices without Windows in the first place.
In my opinion buying a laptop with a Windows license when you know in advance that you don't want it is a mistake. But returning the license would still be better than simply swallowing it. My point is that returning the license alone is (next to) impossible.