I am not sure how people are able to run a 9kg cylinder for 3-4 weeks. I bought a DeLonghi and a Goldair and both use about 150-200g/hour which works out 50-70 hours per cylinder. The Goldair (going for R599 at Builders) has really inferior build-quality when it comes to the heating knobs. Nonetheless both heat very well. Last year I paid in excess of 2-3k p.m. during winter using underfloor heating, so I would think that gas will be substantially cheaper.