Yes it's a thermoquad. Carter made some aftermarket high performance thermoquad's and called them Superquad's.
Like 65Val said thermoquads had issues with the phenolic bowls cracking and leaking and they haven't made new ones for a long time. $125 is a pretty big gamble unless it comes with a guarantee. I have one I picked up for $75 and that's the tops I'd give for one. You also have to be pretty good tuning them as their not your average Carter. To change jets you have to nearly disassemble the whole carb too so their not the easiest thing to work on. But if their working right their fantastic carbs.