Agreed on the name, Palelipped tang is greatly preferred to avoid confusion, and actually more descriptive IMHO. Yes, they are quite rare, the market for a $200 large brown tang is very slim.
I am considering a second tang for my 240 in addition to my Naso. I really would like a Dussumieri, but mostly ruling him out due to size, and it's between a Monrovia, a Palelipped, and a Maculiceps. (Pale lipped is 3rd to be honest)
These are your typical Acanthurus tangs. They stay smaller then Duss's and Blochii's, really close in shape/size/activity level of Sohals/Clown tangs, though somewhat less aggressive then Sohals. I definitely would make this guy your only Acanthurus tang, short of you having like a 400+gal tank.
If purchasing that particular specimen, definitely QT, you can see white spots on the fins.