Those two boxes on the left are audiocom, and are the same series they currently make. The ones on the right are the older audiocom from what I can recall. I have not seen that exact base station or those exact remotes. Looks like early 90's stuff. I know those headsets go for about 150 or so a piece new. I believe BMI is a full supplier of telex, might want to give their catalogs a look to ballpark it. Each one of those boxes usually goes for around a hundred.