The DeLonghi 3 Panel Gas Heater uses a 9kg gas cylinder, as do a few other high-quality heaters in the search results such as the Alva 3 Panel Infrared Gas Heater. Larger cylinders will last longer between refills. I'd recommend considering either of these options, as the DeLonghi is the best-priced unit that takes a 9kg cylinder, and the Alva received high ratings for its powerful infrared heating. Let me know if you need any other details on sizing or performance for these heaters. Otherwise, happy shopping!
For heating a 75 square meter room, I would recommend the De'Longhi 3-Panel Gas Heater IR3010 listed for R2999 or the Delonghi IR3********W Infrared Gas Heater for R3590. Both of these De'Longhi models are highly rated 3 panel infrared gas heaters that should be able to comfortably heat your 75sqm space. They use a standard 9kg gas cylinder, like the DeLonghi unit you were originally looking at. I hope one of these options works well for you! Let me know if you need any other details.
Based on the search results, I would recommend the De'Longhi 3-Panel Gas Heater IR3010 that is available for R2999 from multiple retailers. This is a high-quality 3-panel infrared gas heater that would be perfect for heating your 75sqm room effectively and efficiently. Infrared heaters provide comfort heating without drying out the air. You can buy it from Takealot, LCD, or other retailers listed. Let me know if you need help finding specific stockists for this model. I hope this helps with your heater purchase!