Centurion was a leading name in road bikes from around 1970 to around 1989, when the US importer decided to use the "Diamondback" name on all of their bikes.
Centurion imported bikes in the low, mid, and upper-mid price ranges. Their bikes were well thought of, as they combined some good design ideas, from riders such as Dave Scott, plus Tange steel tubes, and Japanese craftsmanship. At any given price point, they were among the better choices.
I decided to keep my Centurions exactly as they were in the 1980's, so when I replaced the brake levers, I used Shimano levers from the same era. Some folks have taken Centurion frames, and then updated them with a 2004 drivetrain, new wheels, STI shifting and new brake calipers. All of that stuff costs a bunch of money, more than some new 2004 bikes.
The drivetrain is a good clue to the original price level of a Centurion, with Shimano 600 components being used on the more expensive bikes from 1985 to around 1989. However, the Shimano 105 stuff from that era usually works as well as the 600, just a little less cosmetics.