Seems it is a Barco 7 series so a 7" set. The short answer to your question is not much, in fact you may be better off donating it and taking a tax deduction (assuming you are located in the U.S.). Basically the CRT market except for the 9" sets is dead, done, stick a fork in it. And yes I still have a CRT and love it. If the set is in mint then you might get something for it on CL, or Videogon or Ebay (you can state local pickup only). I'd say you'd be lucky to get $100 for the whole set. You might actually get more by breaking it up but I don't know if even the parts have much value anymore other than the HV quad. If you cannot sell it and don't want to donate it you can check with Curt Palme at www dot curtpalme. dot com as he might give you something for a few of the parts.
If you are not in North America then you might or might not have more luck. I don't really know what the markets are like overseas.