Hi Aline
My husband’s got cheap one-way tickets with Tunisia First – from Tunisia/London and vice versa -
http://www.tunisiafirst.co.uk/
Their Tunisian representatives or vice versa is
http://www.nouvelair.com/Publish/indexde.asp
are based at Monastir Airport – I can’t remember if they have flights from Tunis.
We’ve used BA and Tunisair also and have got some reasonably one-way tickets.
He has travelled at not busy times and a few times paid around £80 on a one-way ticket.
L