Used dslr nikon d200.is it a good buy?

Nikon d200 1.5 year used with sigma 18-200 mm lense at $700

or should i go with nikon d90 body and wait for some time to have a good lense (budget shortage)

I'm recommend Nikon D3100 DSLR 14.2-megapixel DX-format CMOS Image Sensor and Full 1080p HD Cinematic Video Price for new $610 it's value your money 14.2-megapixel DX-format CMOS image sensor; 3-inch monitor with One-Touch Live View shooting and movie captureIncludes 3x 18-55mm Zoom-NIKKOR VR Image Stabilization lensFull 1080p HD Cinematic Video with full-time autofocus and soundEasy-To-Use Nikon Guide Mode with intuitive controls and on-board assistanceCapture images to SD/SDHC/SDXC memory cards
Model: D3100 18-55mm Kit
Optical Sensor Resolution: 14.2 MP
Optical zoom: 3 x
Display Size: 3.000 inches
Width: 3.8 inches
Height: 3.0 inches
Weight: 1.11 pounds
Overall:
I give this camera 5 Stars because it takes excellent pictures in almost all conditions (bright or low-light) and that is exactly what I wanted this camera to do for me. Period.

I must commend Nikon for not getting into the mega pixel race (read marketing). They instead kept the photographer in mind and focused on delivering greater picture quality. Kudos to Nikon for having that courage.
Compare Price and Believable Website http://www.babycando.org/review-nikon-d3100-dslr