<p>if you are going for photos of butterflys/reptiles i would look for a used non os sigma 150mm. <br>
my other fave setup for the d7000 and d7100 is the nikon 300f4 af-s with the nikon tc14ii.<br>
the later set up will allow me to "fill the frame" with an average uk sized dragonfly or one of our larger (for the uk) butterflys from its minimum focus distance of 3 feet. it doubles as a great birding lens too.<br>
ok, so its over budget, lacks vr and is on the large side but it is a setup well worth having. it takes a little while to master it and get the best results but when you do you will get superbly sharp results. </p>