If spending $2K, I would get a watch that is actually worth $2K.
Thus, a vintage Heuer Carrera that will likely retain or gain value, instead of a new TAG Heuer Carrera that will very likely lose value.
Aside from the financial aspect, if you care at all what serious watch buffs think, many of them wouldn't cross the street to look at a TAG, but a real Heuer is different.
The disadvantage is that you can't simply walk to a dealer and get one. You have to research, learn, decide, search, find.
For an idea on (the high end of) price ranges -
vintageheuer.com
val.htm
Heuer - Yorktime Used and Vintage Watches for Sale
And for a start on research -
Heuer Carrera Chronographs: A Brief Overview
Oh, also, if you want a Carrera, I'd personally think twice about getting a non-chrono one. The Heuer Carreras are known as chronos, their history and cachet is tied to racing, it is not a "dress watch".