The Beocom 6000 and the Beotalk 1100 are two seperate products. You can use each one seperately and one does not in any way rely on the other to work.
If you are talking about Ebay item number 130216781132 then one picture shows the handset on a charger base, but does not talk about the PSTN.
For the Beocom 6000 to work it needs either a base with intergrated PSTN (Old type) or a seperate PSTN like the one HERE
The sound quality is excellent and certainly better than the average BT phone.