About a dozen with one of them, the other not so many.
And you know what? That's okay. Like Haggis said, the early stuff ain't gonna be that great. But I'll pull the parts off that work and use them in better stories.
You giving up far, far too soon. I've made some of my best, biggest, and most lucrative sales after two dozen or more rejections. As long as there's a possible market, giving up on a story is a bad way to succeed. I've seen stories rejected several dozen time, and then sell to a top magazine. Heinlein's Rules work. They simply
work, if you follow all five, and don't let anyone talk you out of doing so. Many will argue these rules to death, especially rule two. Ignore these people. They know not what they do. Read this, all of it, and
believe it.
http://www.sfwriter.com/ow05.htm
As for early stuff being bad, everyone says this, so it must be true. But if it is true, how do explain the hige number of very first short stories that sell? Or the number of first novels that sell? If you write with the attitude that your early stuff will automatically be bad, it will probably be bad. If you write with the attitude that it's going to be good, it will, if you have talent, and are an experienced reader, be pretty darned good, even if it doesn't sell. But a lot of it will sell, again, if you have talent.
My experience is that talent usually shows up early, or it doesn't show up at all. But here's the thing. If you follow all five of Heinlein's Rules, you don't have to worry about it. You need have no faith in your short stories, as long as you have faith in the rules. Rule four is "You must put your story on the market." Rule five is, "You must keep it there until it sells." It's just this simple.
Break these rules and you may still succeed, but doing so is far less likely. The funny thing is that even those who argue against the rules follow them when they make a sale. Follow the rules, and your chances of succeeding go up
dramatically. But you probably can't make yourself follow all five. They're incredibly simple rules. They almost ridiculously simple. But from my experience, only about one writer in a hundred can actually follow all five for any length of time. The other ninety-nine find all sorts of excuse not to follow them. But any story you sell probably follows all five rules. Sawyer adds a sixth rule that's equally simple, and equally important, but few can follow it, either.