board over the artex with 3/8 plasterboard -just make sure you tack the nails into the ceiling joists not just the existing board -use galvanised plasterboard nails about 40mm long- then plaster with multifinish plaster cost around 3-400 quid for a 30msquare ceiliing around a fiver for a sheet of board -- youll need 11 sheets about four quid for a bag of plaster- youll need two or three -- a roll of scrim (for the joints) about a fiver for nails -- a stanley knife for cutting the board etc---- if you go the uni bond way then it will take longer to dry(more moisture to your boards) the boarding and plaster will be dry in a few hours-- dont forget to seal the plaster with a "mist " coat of emulsion before you paint it
oh and about a tenners worth of tea and coffee
[Edited on 23-5-2005 by monstermob 998]