Officially one bottle of spirits each, though as the Duty Free at UK airports often seem to have offers on two bottles and I travel solo I've usually taken in two and have never had any problems. I certainly wouldn't risk taking in more than 2 bottles each though. Your impression is right though - all imported spirits are very expensive in Tunisia.

To be quite honest, whenever we go, we take as much as we can afford/carry! I know that the limits returning to the UK are in accordance with EU regulations, but as Tunisia is outside of these borders, I don't think there are any restrictions. My husband is Tunisian though and it may just be that a blind eye is turned for him. I don't think thats the case though and I'm sure as long as its not tens of bottles, you'll be fine, with whatever you take. As already mentioned spirits are really expensive as they are imported, unless obviously its the local firewater. Hope that helps.

There are actually quite strict limits on what can be taken into Tunisia and they are surprisingly low, as you will see from the link below, but as soussegirl says, you can often get away with more:

http://www.worldtravelguide.net/country/283/duty_free_section/Africa/Tunisia.html

I found the wording on that webpage you linked rather interesting:

(Post edited for copyright reasons, but the comments removed can be found in the opening paragraph on that webpage ... David HT Mod)

Reading that it means you could get your kids to take in extra bottles of Spirits