I subscribed using this service when I first came to Qatar:
300 QAR per year (equivalent to monthly subscription of 300/12 = 25 QAR), and Q-tel would bill me charge whatever minutes I call at the normal rate (around 0.35 QAR / minute?) and no free SMS'.

Once my bills started exceeding 200 QAR per month, I switched to Shary Value Pack - 200: I pay 200 QAR per month and get 600 minutes (whether I use them or not) of air time to other Q-tel lines + 50 free SMS + some Internet access. Not sure if talking to Vodafone subscribers will be charged separately though..