1. And if you know what are you doing.
2. you don't need bank account
1. Why someone claim about anonymity by default - this is a question.
2. For a credit card don't need bank account too.
Buying Bitcoins at the street or on exchanger produce paying fees.
For example, the Russian page of the site in my signature provide payments from
WebMoney
Дeньги@Mail.Ru money-mail.ru
Яндeкc.Дeньги money-yandex.ru
QIWI
And QIWI is an anonymous cash terminal (i'm thinking, it's anonymous).
People have enough possibilities to pay without checking $/
BTC exchange rate