I have a few semi valuble/rare comics (crisis 7, the batman 'death in the family' issues, ect. anyways, would it be worth it to sell some of these off to get some extra cash, or is it more likely that they'll stay on ebay without any bids and me stuck with paying the ebay charges. or should i just hold on to them, maybe hope they go up in value.

Hold em. Those aren't exactly rare/valuable issues anymore. Your going to need some Gold and Silver to make money, and even then if they are not CGC graded, you wont get a full value. Which opens another topic of graded books pushing out sellers who don't do this...

Those aren't exactly high-demand issues, and probably never will be.

The unfortunate truth about comic books is that once the direct market came into existence, it killed the collectibility of comics. Once you had all of these specialty shops open up that catered to collectors, it pushed the supply of high grade issues up to the point they're essentially valueless.

Combine that with the fact that the publishers have been churning out so much material over the past couple of decades, they've also contributed to a glut of comic books. There are already thousands of different Marvel and DC Comic books out there, and more coming each month, and all at high cover prices.

I also think that the recent phenomena of downloading comics (either legally or gray market) is also contributing to a decreased interest in back issue comics.

Just search ebay competed auctions to see what your books are selling for. Factor in fees and decide if it is worth it.