Your series is getting interesting. Exposing us to alot of exchanges out there. That's wonderful.
I'd like to add more info to what you have:
Based on verification provided, cex.io has four different account levels. Your daily buying limit is dependent on your account level.
There's the basic account, which can buy up to $400 worth of bitcoins per day, and up to $2,000 per month but cannot buy via bank transfer.
There's the verified account, which can buy up to $10,000 worth of bitcoins per day, and up to $100,000 per month and can buy via bank transfer and credit card.
Then there is the individual business and also the corporate account that can buy unlimited amount of bitcoin.