DON'T TEST FIRE THEM WITHOUT AIR!!!!!!!
*edit*
Sorry for the immediate dramatic post there, but I wanted to get a post up ASAP, so I could then take the time to write a longer and more thoughtful/helpful post. Airguns do NOT like to be dryfired if there is no air in the cylinders to oppose the hammer. Doing so even once can ruin the valve stem, which particularly on the Rogue you probably don't want to have to figure out how to replace.
The current Evanix Rainstorm II new is about a 700$ gun if memory serves. The original bullpup was somewhere in that range, but wasn't particularly desirable if memory serves. If yours is in really mint condition, holds air, shoots well, etc I don't think you'll get more than 600$ for it in the classifieds unless you find that one guy if you know what I mean. I am not the one to ask about the Korean guns though, so people should please correct me if I'm wrong. If you don't have the equipment or inclination to pressurize or test it, so have to sell it in unknown condition and as-is I'd figure you're in maybe the 2-400$ range. Again if you can pressurize it and test shoot it and everything is great you can sell it for a lot more than if you just have a couple pictures and say "as is."
The Benjamin Rogue is a bit more of an interesting thing. I think they were about 1.2K new, and had some fancy electronics on board to run them. For whatever reason though, they were never particularly popular. This was probably in part the lack of available well priced air compressors to feed them, and in part because all the field reports on them at the time showed pretty poor accuracy. I sort of expected them to develop a cult following once discontinued, however if there is such a cult I haven't seen evidence of it. Again don't dryfire it without air in the cylinder, but if it will hold pressure and the electronics power up and appear to be working it is probably worth considerably more. Again my personal rule of thumb is that unknown as-is condition on a product is generally a quarter of retail value, so somewhere around 3-400$ maybe? Flip side of the coin is if you can test the condition and you can find that one guy who really wants it, he might pay a pretty penny for it maybe even more than retail. I just don't know.
Full disclosure A) assume I know nothing, after all I'm just some dude on the internet. If someone else comes along who knows better PLEASE correct me and B) years ago I wanted a Benjamin Rogue and never got one, so assume I'm some kind of dirty filthy liar trying to cheat you and get at least one other person's advice before listing it.
I hope that was some sort of helpful.
*edit2*
Also if you're wondering why you can't list things in the classifies yet, it is because you have to be a contributing member of the forum before access to that is unlocked.
