I have seen several sources citing that AMD is going to have a price cut on the HD48XX series around the month of July. The main reason for this is that they can not produce enough 4770s to fill that market niche, plus the new HD58XX series will be releasing around the September - October time frame so they have to clean out their stock of 48XXs.http://www.fudzilla.com/content/view/14223/34/
This is a no-brainer. The HD4850 with out a doubt. From what I understand they are going to drop the price below the century mark. The yields on the 4770s are not very good thus increasing it's production costs.
I don't have this card but I would highly recommend the HIS ICE-Q4 HD4850 Turbo. SPEND the xtra money on it. It is worth it.