If you have a DSLR, you can easily spend more on lenses than the camera itself cost. Luckily there are a few great lenses you can buy for under $200. I will highlight two of my favorites here.
Everyone should own Nikon’s wonderful 50mm f/1.8D AF, which sells for under $140. This is one of the best lenses you can buy because it’s extremely sharp and the large aperture lets you shoot in low light and blur the background nicely. It’s my favorite lens for those reasons.
Note that this lens lacks an internal AF motor, so if you have a D40 or D60 you can only use manual focus with it. If you have one of those cameras and you really need auto focus, Nikon also sells a 50mm f/1.4G AF-S, which costs around $480.
If you need a long zoom, Sigma’s 70-300mm f/4.5-6 DG Macro is a good choice for around $150. This is one of the longest lenses available at an affordable price, as most similar lenses only go up to 200mm. It has a macro mode available from 200-300mm which lets you focus much closer and gives a 1:2 close-up magnification. Since it lacks vibration reduction, you’ll either have to use a tripod or shoot at a very fast shutter speed, since the long focal length amplifies any camera shake. On the plus side, the image quality is excellent with less distortion than Nikon’s 18-200mm.