I'm not sure but there are a lot of people complaining about them recently so If I were you, I wouldn't use them now.

Yes it'll be expensive compared to normal because of the network congestion, I think your deposit has to confirm in the nearest block as much as possible because I've seen a lot of users whoose transaction (deposit) got stucked for days and it's either "trade failed" or stuck to "exchange in progress"if it ever confirms after those days. As for withdrawal fees they released a list of it, since exchanging in blockchain.info is powered by shapeshift, I think these also applies to them https://info.shapeshift.io/about