New updates:

( sorry, but I cannot edit previous messages

)
1.
Zelta zivtina changes costs for data add-on (eg beneficial data transfer tariff), now is LVL 0.022/MB - € 0.031/MB.
2.
Amigo has changed costs for voice/sms/data and now doesn't offer good bonuses with refill vouchers:
Voice tariffs:
Mo-Su 0-24
Calls to Amigo: LVL 0.03 - € 0.043
Other calls: LVL 0.10 - € 0.143
Messaging:
Amigo and LMT: LVL 0.02 - € 0.029
National SMS: LVL 0.05 - € 0.071
Customer Service 26200000 or 1661 (free of charge)
Data Calls:
LVL 0.30/MB - € 0.43/MB
Internet add-ons:
1 day (30 MB): LVL 0.25 - € 0.357 - activation: write i to 1688
10 days (500 MB): LVL 2.00 - € 2.86 - activation: write i10 to 1688
30 days (2 GB): LVL 5.00 - € 7.14 - activation: write i30 to 1688
Recharges/credit/validity
LVL 0.99/1.00, 10+60 days
LVL 1.99/2.00, 20+60 days
LVL 2.99/3.00, 30+60 days
LVL 3.99/4.00, 60+60 days* - see information above
LVL 4.99/5.00, 60+60 days
LVL 9.99/10.00, 120+60 days
LVL 19.99/20.00, 365+60 days