used $300 max (I know, I'm asking for a lot)
The Taurus model 82 fits that pretty neatly.
Now, you're on a roll. I think that is a good first choice for a gun in your price range. While I am not a big fan of Taurus autos (had one that broke), their all steel revolvers aren't bad for the price. They are fairly rugged and certainly reliable. The ability to shoot .38 special out of a .357 revolver is a real plus. Look for one that hasn't been shot a lot. It would be best if you can handle the revolver, feel whether the cylinder is nice and tight or lose, work the action to make sure it is smooth, make sure cylinder isn't rubbing on anything as it turns; look at the bore with a bore light and make sure it is nice and shiny; and generally make sure it hasn't been abused. The condition of the external finish can be an indication of the care the previous owner used in maintaining the gun - not always, but often.
If I were you, I'd jump in and buy that gun when you find the one you want in the best condition you can afford. If/when you want something different, then sell it or trade it - if you buy it used and shop around for it, you probably wouldn't lose much on a trade down the road.