Nikon D3100 Fisheye Lens?

I'm a beginner photographer and I just got a Nikon D3100 with a standard 18-55mm lens a few months ago. I've been wanting to get a fisheye lens but I'm not in a position to spend more than $200. I've been looking for a lens that's reasonably priced but can't seem to find one. They're all $300+. Can anyone help me out?

Yes, I can help you out. Don't buy one. With cost, comes quality, or lack of. Do you really NEED a fish eye lens? Most of us don't. There are no reasonably priced fish eye lens. You'd get more use out of the 55-200mm lens Nikon makes. It's $250 brand new. Refurbished, maybe $100 cheaper.

Unfortunately, there are no really cheap fisheye lenses out there. My suggestion is to try and find a used one (on amazon, ebay or adorama.com for example).
An alternative would be a wide-angle fisheye converter that goes onto the lens. Look for a 52mm one for the 18-55mm.

However, the quality of the images is not gonna be as good as if it was taken with a real fisheye lens, but it might be enough for your needs. It's only a cheap alternative, and in photography it's always "you buy cheap, you buy twice", because as Vinegar Taster pointed out, "With cost, comes quality, or lack of."
So always be careful with cheap stuff. You're better off if you wait till you've saved up enough money for a proper lens.