Eventually it is a Queen's Gambit accepted, but a more usual move order would be:
1. d4 d5 2. c4 dxc4 3. e3 Nf6 4. Bxc4 e6 5. Nf3
From the white side, I don't see any advantage in playing 2. Nf3 instead of 2. c4. From the black side, you don't need to let white transpose back to a normal line. After 2. Nf3 you can play 2. ... c5.
I didn't like 5. ... Nc6 because it blocks black's c-pawn.
Do you know this opening? if you do please tell me it's name. is it some sort of a queen's gambit, is this a good opening?