Late to the party

So I have been sending out the queries, hitting up the agents. Doing the grunt work that is always necessary to get ones work published, and it dawned on me. What if I am already late for the party? When I started writing my 2nd book I really didn't have any ideas in mind as to what it should be about. I just wrote a story and let the characters tell me what they were going to do next. Mix in a few disasters and some really bad luck and viola! A story! But now that it is finished I have found myself stewing with a few thousand (or even more than that) other people who have all written stories like mine. (Yes mine is original, in more ways than one, but they still use a lot of characters overpopulating books these days, werewolves for instance, and yes one vampire...sorta.) So the question has once again come up. Do I sit on this story for years waiting for the market to flush itself out and allow a story like this to come around again, or do I self publish it, in the hopes of sales now on the tale end of the parade. The more I think about it the more I think it is time to put it up for self publishing. I have two short stories up for sale now and the third is over half done. The forth is itching at me to get moving since I have it already planned out. It won't be hard to finish it and get it up there. The fifth and final of the series will take a little longer.
After all, this isn't the last book I am going to write, in fact the more I think about it the more I really want to pick up that first book I stared on, fix it, finish it, and send it off for publication attempts. The story I had started (50k in) and outlined almost to the end, is unlike anything I have read (yet) and it has memorable, lovable and relate-able characters. The odds of it doing better in a field of books where people are looking for something fresh and new are much higher.
So that being said, it is time to get back to the editing work. Regardless of the end decision, I need to finish cleaning up my grammar and punctuation. If I don't do that, no one will want to read these stories no matter how interesting they are.
As a completely different side note, I have a friend helping me work on a "trademark" for my writing. A button that others can have on their sites that will link back to me and my writing. If you have any suggestions I would love to hear them. Right now I am thinking a different twist on the old phrase the pen is mightier than the sword. Suggestions? Let me know in the comments.