I'm helping out a friend with an estate sale in which there are 8 Marlin 336's in .30-30 ranging in condition from like new to fair/poor.
I know I've seen new 336's in Wal-Mart for around $300 last time I looked.
So whats a fair good deal on a used one.
Wal-mart ones are a lesser grade than Marlins with the Marlin Bullseye. With all the talk about how Marlins quaility has gone down since moving, you may have some fairly valuble rifles at the moment. The like new you could get maybe $450 or so if it is nearly mint and it's not a chain store model. Then again, you may get even more depending on how much someones willing to pay for a pre-remington version. You can probably judge from here as to what the others may be worth.
Not a clue on the better condition stuff, but with the popularity of tricking out MArlin's into every possible type of configuration (take downs, WWG style, Scout style rifles - and the like) you should still be abl to a couple hundred bucks for the rough ones as long as the bores are good
I bought my 1949 made Marlin 336-A with slight rust patina, worn bluing and a cracked stock (minor) that had it's 24" barrel cut down to 20" for $275.
I know it was a bit high but it was private party sale and was well seasoned with nothing broken.
it turned into a project gun and this is the result.