Where to buy second-hand products of Knauer?

Hi,

We are in Germany and interested in the following products:

1. Knauer Smartline system Analytical HPG configuration with fiber optics detector- SYSS002

2. Knauer Smartline system Analytical LPG configuration with UV detection (system proposal)- SYSS003

However, the prices of new products are quite high for us and we prefer to buy second-hands. Indeed, we cannot find any of Knauer´s second-hand products (especially these two types) on any website. Could you please be so kind and help us by telling where/how can we find their second-hand products?

Also please note that we don´t have boundary for location and can buy it from any country (but Middle East is most preferred)

Patiently looking forward your reply,
Thank you
Regards,