While there is a narrow price gap between the HD6670 (~ $50) and the HD7750 (~ $90), unless this card drops at the 65- to 70-dollar range of its speculated pricing, the proven and readily-available HD7750 is simply a better buy.
During sales/promotions, as well as through rebates, HD7750's have lately been available for between 75 and 80 dollars. That's what makes me feel this HD7730 should be priced at roughly $65. If it's any higher, a patient buyer who seeks out the best deal (or anyone who bothers to use pcpartpicker) can get an HD7750 for nearly even money.