Depends on payment method. If you buy with credit/debit card, express cash transfer or prepaid voucher, it's instant. But the initial limit for buying with card is $100. You can read about credit card purchasing limits here: http://247exchange.com/limits
If you use a bank wire transfer, it's usually arrives in 1-3 business days, SEPA transfer - in 1-2.
To calculate the actual amount you get, please use this form: http://247exchange.com/buy