You could always use the big UK-based exchange:

Bitstamp charges a small 0.1% fee (one tenth of one percent) for International bank transfer deposits, and 0.50% (half a percent) fee to use their exchange for small quantities up to an equivalent 500 US Dollars, and a reduced fee schedule which will go as low as 0.20% if your 30-day volume is over 150 thousand dollars. To get verified (full access), you'll need a valid government issued ID, and a proof of residency... I was curious so I tested to make sure they allow signups from your country:



^That's a screenshot of the email I got during signup for a test... It let me choose Venezuela during signup and everything works, but I think my browser cookies caused the default currency to show up as USD instead of GBP, Euro dollars, or anything else... That shouldn't matter so long as you have the ability to send international bank transfer to the exchange to be able to buy bitcoin.

Good luck