Server crash script

I found a simple server crash exploit, and I have seen scripts like this sell for +$100.
So what do I do? It has only been used 2 times by me and has not been patched. What do you guy think?

Release it. Keep it to yourself. Do anything you want with it...

If you release it, it'll get patched by Valve in the next update. Well, selling is an option here, but this doesn't give the guaranty, that it won't be leaked and patched the same way. Only if you need these few bucks badly... Btw I doubt that anyone would buy it for $100
I'd keep it to myself and pray that Valve doesn't know about this exploit if I were you.