The information on Xaxrax Sigma, as seen in The Hitchhiker's Guide to the Galaxy TV series.
Xaxrax Sigma is a planet in Sector XXXZ5QZX on which The Evildrome Boozarama resides, which is seen as one of the best places to get a Pan Galactic Gargle Blaster. One can expect to pay 75 Altairian dollars for a Pan Galactic Gargle Blaster on this planet.
This is according to the information in The Hitchhiker's Guide to the Galaxy under the topic of Alcohol which tells you on which planets the best Pan Galactic Gargle Blasters are mixed, how much you can expect to pay for one, and what voluntary organisations exist to help you rehabilitate (as shown in the TV series).