Im looking to get a telephotof or christmas. The price range is around 200 so its ganna be pretty tough. Just wondering if anyone has had any expirience or reviews on these lenses. http://www.bhphotovideo.com/c/product/446042-REG/Tamron_AF77017C_28_80mm_and_70_300mm_Di.html http://www.bhphotovideo.com/c/product/391074-REG/Sigma_508101_70_300mm_f_4_5_6_APO_DG.html Which one would be better? and are there any other lenses that would be better around this price range? any help is greatly appriciated, thanks in advance!