So there's this anthology looking for stories on a specific theme, and, if accepted, you'll be paid $500 for your story. Not bad, right? Except there is one little important detail worth mentioning (the bold is mine):
I am looking for 10-12 publishable stories by new and upcoming authors, and I will see that you are paid $500 for your story, though it may take some time for you to receive your payment as I have to get an agent and publisher on board with this project. I will also solicit 2-4 stories by better-known authors in order to make this volume a bestseller at Jewish book fairs.
So right now, basically, there is no money. There could be, somewhere down the line. But publishing being publishing, it's just as possible (and quite likely) that there will be a big load of nothing when it's all said and done.
Not that I'm trying to discourage anyone from submitting to this market. For all anyone knows, the editor could quite possibly secure an agent and publisher and the anthology could be a big success. But I've seen these types of guidelines before, a hopeful editor offering an incentive that he or she doesn't have and quite possibly never will have. (Also, let's not get too much into the math here, but 10-12 publishable stories x $500 = $6,000 at most, and that's leaving the editor with nothing. Is that kind of advance believable? If you have a new Stephen King story, sure, though he alone will probably require at least $5,000.)
This happened to me a couple years ago: I sold a story to a themed anthology and was supposed to be paid a nice amount for it. Only thing was, the editor was still searching for a publisher. But if and when the project did find a home, then I was promised to receive said amount. But the project never came together, and quite honestly, I wasn't too disappointed as the story was a reprint to begin with. It wasn't like I had written it specifically for the anthology in question and then waited and waited and waited for nothing to happen and then, when nothing did happen, I was stuck with an unsold themed story.
And then, sometimes, a project is all set to go, there's a publisher with money, and then it all falls apart in the end anyway. This, too, happened to me years ago. It wouldn't have been such a big deal (shit happens, right?) except I later learned that some of the contributors had been paid upfront, while others (like myself) were not paid a cent.
Anyway, I think a lot of editors and publishers start out with good intentions. But sometimes I think a lot of editors and publishers promise more than they can really deliver. So it's always important to stay alert and remember that if it's too good to be true, it probably is.