Upgrading from EF-S 18-20mm.

[neuroanatomist]

If 200mm is as long as you need/want, the 70-200mm f/4L IS is in your budget and is a versatile and excellent lens (optically pretty much equivalent to the 70-200/2.8L IS II). If you just need 200mm, the 200mm f/2.8L II is also an excellent lens, and a great value.

[DSLR_Newbie]

If 200mm is as long as you need/want,

Thanks for the reply.
Range over 200mm should be fine as long as it does not degrades image quality for the extra reach.