Well I'm on 30mbps plan atm.. and it's 15euro/month. All I can do is move to another company and I will get 50mbps for the same price. They both claim they use optic cables but the one I'm with now uses such only on some places.. The cable that comes to you is normal copper cable.. And as for the other company - I can't be sure unless I move to them(the site says that you can have "you own internet with optic fiber in your home"). But I got a bit out of my point... It was actually that the highest speed you can get in here is 100mbps and that costs 30euro per month.
Here's the site tho(you can get exact prices too.. they are in BGN - bulgarian value): http://pon.bg/index.php
And my current isp: http://www.interbild.net/ (prices: http://www.interbild.net/prices ) ..Guess what tho... I get 10mbps at max on speed tests.. Actually I normally get around 5 to 6.. But speeds aren't guaranteed so I can't do poo about it