Small businesses will be slugged up to 24 per cent more for gas from next week, with firms in Kalgoorlie and the South-West bearing the brunt of the rise. Gas prices in the Perth metropolitan area will jump up to 9 per cent, while firms in the Albany area and Kalgoorlie face increases of about 20 and 24 per cent, respectively. Alinta said prices in the Mid and South-West had been artificially low for "some time".