If you need a new water heater the most cost-effective option in the majority of cases is instant gas water heating – even if you don’t already have gas connected to your home.
The low up-front purchase and installation cost of instant gas water heaters, combined with the low price of gas (relative to electricity) makes instant gas water heating more cost-effective than other options.
If you have an existing hot water cylinder heater, it isn’t generally cost-effective to spend money on replacing it with an instant gas water heater - although for people who use a lot of hot water the cost difference is small. That’s when the lifestyle/quality considerations may come in to play in your thinking. Never running out of hot water is identified as a key benefit of instant gas water heating compared with all other options. And as all other options involve cylinders, a further benefit of a continuous gas hot water system is that it can free up space in your house.