🚀 go-pugleaf

Hello everyone, the equipment budget for the department I work in has
been slashed to zero, and our line test set got stolen recently.  
I've been wondering if anyone knows what justifies the $200-300
cost of such a beast.  Is it because it is a speciality market,
or are there components in there that are really worth a couple
hundred dollars?  I've added up the cost of the obvious components
(headset, tone pad, aligator clips, batteries, isolation transformer)
and arrive at about $50.  The only thing I don't know about is the
monitor option, which is what I use most to debug the modems.  What
makes up this circuit?  

One final thing, does anyone know if I can use the telephone
isolation transformer on an old 300 baud modem to shave a couple
dollars?  We've got some 300 baud modems around collecting dust.