I actually recommend getting the Tamron 17-50. It can be bought for around 300-350 and it's one of the best lens Tamron has ever made, the image quality rivals the Nikkor equivalent (17-55). Pair that with the Nikkor 55-200 and you're pretty much covered. Another lens worth looking into is the new 35mm prime. Total cose for these 3 will be around 700-800.