I don't know where you guys get that the Marlin is over all better than the Rossi/Puma 92's and where you are getting your prices at. The 92's have actions just as strong if not stronger, they are slicker and they have a better "lightweight carbine" feel. Overall it's pretty close to a dead heat. The Marlin can be scoped which is an advantage to some. Only way to tell which one you prefer is to handle both yourself.
But a Marlin 1894 for $500 or less? Not on the new market and rare in the used market.