We have an unlocked Blackberry Q10 phone with GSM capability. We were planning to purchase a SIM card for it in Czech Republic at the airport (Vodaphone as recommended by a few other posters.) As I was trying to read the details it is not clear to me that I could use that same card in Hungary without paying expensive roaming charges. To anyone who has used this service before, did I understand that correctly? Does anyone have other suggestions? We primarily need to use the phone to call and confirm our arrival time at bed and breakfast hotels, call a taxi, etc.