I can't help regarding mini buses but I've had a Tunisiana SIM card for years. They cost approximately 10 dinar and you need to present a photocopy of your passport. A 'top up' of 5 dinars will keep your number for 3 months and 10 dinars or more will keep it for 6 months. I use it mainly to text home as I find the prices from hotels are horrendous though the public taxi-phones are very reasonable. Don't forget if you use your English phone to phone another English mobile whilst you are abroad, though you may actually be in the next shop, the call will go via the UK and will be charged accordingly.

Cheers for that Aslemma :-) got mini bus sorted, for 8 of us one party booked transfers with holibobs, so sending 2 of the group on the transfer bus, whilst the rest of us go in the mini bus, I am only going to use the sim card for texting, do you think I will or how do I top up, just in case I run out of credit ? Is 10 dinar, already on the sim ready to use for texting or do I need to top up more to txt while me there ? First time I a have ever got and used a tunisia sim card, 1st time for everything, lol, previously just used me normal service provider, but going to be switching service provider when we are back, so begrudge topping up some silly amount to use while there, does that make sense, :-)
Thanks again :-)

Sorry for not replying earlier but I didn't get the usual notification of a new post. I can't remember the exact details of a new Tunisianasim as it's a long time since I got one but you can top up anywhere you see the Tunisiana sign. I agree it would be silly to put a lot of money on your English sim if you are changing providers. I take it that you have an 'unlocked phone. I actually have a better idea which you may like so am sending you a PM.