If you live in Europe you can send money from your bank to an exchange like Bitstamp for 10 cents, if you live outside Europe it will cost $10 or more. After you get money onto an exchange you can put a buy order on and wait until someone sells Bitcoins into it. That gets you a better price than buying into a Bitcoin sell order. You will get charged between 0.1% to 0.5% for the trade. Finally, when you withdraw your Bitcoins there might be a withdrawal fee. Bitfinex does Bitcoin withdrawals for free, but it was hacked this year. Bitstamp also does free Bitcoin withdrawals, but it was hacked last year. Other exchanges have varying fees.