So here is the back story:
I found a listing on Craigslist for a Nikon N65 with a 18-135mm DX lens for $90. After several emails with the owner, I decided to buy it. Problem was I was not around to view before money was exchanged, my father actually picked it up for me as it was near his house. After, I received the lens, I looked it over and did not see any problems with it at the time. Now flash forward a month to the present...I was looking at the lens lastnight and notice that when I hold it to take a picture in a portrait position, there appears to be something loose near the middle of the cylinder. Also noticed the possiblity of some fungus that I had not seen before.

Now my question to the experts here is...is it worth paying to have the lens repaired? At this point I am only out $90 on a lens that seems to retail used in the $200 range. Or should I just save my money, as I already have a Sigma 28-300mm and hold out to buy something wider in the future? My intension was originally to keep the 18-135mm and sell off the 18-55mm kit lens.

Other pertinent info: Current camera is a D80, hoping to upgrade to a D90 sometime this year.

I'd say to have it cleaned and fixed, your going to be in atleast another $130.

Find a decent local repair person and see what they say.

You can get rid of the fungus for free by setting it outside in direct sunlight for a few hours.

If it has fungus on it, you can never be totally rid of it and it will eventually infect all your other gear. Get rid of it ... it's only $90 bucks.

When someone is selling something for $90 that normally sells used for $200 that should have been an indication to you that something was wrong with the lens and that much closer inspection was needed before completing the sale.

^ +1. Save the rest of your gear... toss the fungal/busted lens. Chalk it up as a lesson learned, and pick up another DX zoom to replace it. I recommend the 18-70mm f/3.5-4.5 or the newer 16-85mm f/3.5-5.6 AFS VR.

At this point it sounds like saving my money is the best thing to do. I have made sure to keep it away from the rest of my gear as soon as I saw any sign of fungus. I might see what I can do about taking it apart actually. Always wanted to see what the inside of the lens actually looks like hands on.

Thank you to everyone with the suggestions to this point.