I ran the numbers, looks like the Coles powered, which works fine for us on mains water no issues, is about 9 cents a wash, using less than 25 grabs powder at $0.39 per 100 grams. The powder goes in the doeser, plus a small amount in the main compartment so the first rinse cycle is doing a pre-wash.

No Aldi here in Tas, but I'd have to break the tables to approach price competitive.