in the UK the prices are
Gold - 12 Month £39.99
Gold - 1 Month £5.99
Gold Family Pack (4) - 12 Month - £69.99
EDIT* I just noticed that your asking about xbox live in Slovakia.
apparently what you can do is get someone to create an xbox gamertag for you in a supported country and then recover it in slovakia you can then add prepaid cards to it which you can use one of the online services to purchase prepaid xbox codes (i.e http://live-codes.com). This is just after doing some research so if anyone else can confirm or deny this?