Stevobeevo,
Flybe's AMS service is operated in codeshare and is actually a ScotAirways Dornier 328. The CDG flights are AF/BritAir CRJ's and as such the truly low cost fares are not available as it is not a Flybe flight.
You will find that Flybe's own routes from SOU to Guernsey, Jersey, Belfast, Dublin, Milan and Geneva all start at £58 rtn.
Flybe have also indicated that they may start additional flights from SOU to some of the BUZZ destinations, likely to be southern Spain....remember BUZZ flights to Malaga/Murcia started at £98 rtn!!!....expect Flybe to be very similar, if not cheaper if these additional flights get the go-ahead.