Hi everybody, signed up to the forum a few minutes back. Have been reading posts and views and whilst asking the question am feeling nervous about the comments from the experts like msmoto, adamz taotejared etc. Well straight to the point - I am planning for an African Safari trip next summer and feel that I badly need Nikon 14-24mm f/2.8 and Nikon 500mm f/4.0G ED VR AF-S for this trip. None of these are available on rentals in the country where i stay currently. I have recently purchased D600 and have the following lenses - Nikon 70-300 VR and a Tokin 11-16mm. Whilst I want to build up my glass collection (I have recently got into photography as a hobby-1 yr), can't afford 14-24mm f/2.8 and 500mm f/4 now. What could be the cheaper alternatives (without much sacrifice in terms of quality and ease of shooting) so that i can come back with great pics of the animals and birds ? My budget is USD 2.5 k. What are the best equivalents from 3rd parties like tamron/sigma etc ? Will the IQ from 3rd party lenses like Tamron / Sigma be at par ? Just want to have some nice 8" by 6" shots for hanging at home. Thanks in advance for your guidance and tips.