2...c5 loses a pawn. If White wants to, he can just take the c5 pawn. Then the Black's knight takes the pawn. Sure, Black has a developed knight but, with a whole pawn down, I don't think it's worth it. Also, White will be able bring his kingside bishop in one move and will be able to castle in about three moves, while Black will need an extra move for his bishop. I don't recommend 2...c5.
This forum is dedicated to the study of Scandinavian Defense with 2... c5:
1. e4 d5
2.exd5 c5
This is my novelty that I have analysed in great depth and will post my analysis here.