4850 1gb Or 5770

im planning to get a graphics card for my pc.Its mostly for SC2 and BC2.im not planning to use this card for a realy long time (around 1 year)..
4850 costs 110$ at newegg.ca
and the cheapest 5770 costs 165 at newegg.ca
is the 5770 worth the extra 50-60$?
btw my screen res is 1440X900