As far as I know Cameron's line has only offered milled steel Bullseye style putters a couple of different times, each for about a 2 or 3 year run.
Depending on condition, the Cameron steel Bullseye putters usually sell from about $80 to $300.
Over the years Cameron made "Tour Bullseyes" for players such as Tom Kite, Andy Bean, John Cook, Peter Jacobsen and more. Compared to the consumer retail models, The Tour versions usually have different stamps (or no stamps) and finishes . The Tour versions seems to sell for between $500 and $1,500.
Also, 20 years ago Cameron reworked the traditional Reuter/Acushnet brass Bullseye which was popular for decades. I'm not sure this "Cameron Brass Bullseye" was ever part of Cameron/Titleist putter line. Instead it's been used for promotional purposes, such as when Ford or Coca Cola need 200 putters for an event Titleist will sell the brass Bullseye with the Coaca Cola, Ford etc.. logo on the putter face. These brass Bullseyes have an SC (Scotty Cameron) stamp on the sole of the putters.