We are always looking for lenses for a low price, so welcome to the club. Hit up craigslist, the buy/sell forums here, adorama, b&h, KEH, ebay. Be careful, be selective, and don't be afraid to buy used...just know what you are buying. Do your research.
Cheap lenses often have poor IQ, or if it is a good lens offered cheaply... may have issues the seller is not telling you about.... so be careful! You often "get" what you pay for!
So for about $915 plus shipping you could pick up a full range of primes, 24mm f2.8, 35mm f2.8, 50mm f1.4, 85mm f2, 135mm f2.8, 180mm f2.8. But you would have to sacrifice metering.
I want a longer zoom lens I'm very new to this. I just didn't know if any lens would work or just a special kind. Im 18 starting my senior year in highschool and I dont have a lot of money to spend on a lens. I just want to buy one for long distance things.
I have a Sigma 70-300mm 1:4-5.6D APO Macro you can have for $30 . . It needs a body with an AF motor to auto-focus, and I am thinking the 5100 does not have that?
I just think it's kind of pointless to seek a new lens without knowing what you want from it. If you said you were looking for an affordable telephoto zoom, that would have been different.