I like the idea of taking a risk on a young potential star like Dybala. Cavani was one we chose not to take the risk on, when he was available from Palermo, and look how he turned out for Napoli.
Guys like Amauri and Matri, and other such had obvious limitations to begin with, they could be decent players, but were technically limited players. They were also in the their mid-20s when we bought them.
Dybala is 21, and seems like the sky is the limit as far technical ability and skill goes. He could develop a little more physically, get a little tougher, but aside from that, this guy has everything. He's agile, has good pace, quickness, excellent dribbling, close control, off-ball positioning. Good finishing. Excellent creativity. Even his hold-up play is fairly good.
Cavani was much the same in his Palermo days. He was young, not fully developed physically, but had everything needed for future success.