Natural gas hot water heater leaking will replace Monday. Any recommendation on what to replace it with? Does anyone have one of those tank less ones. How expensive is it?

Love my tankless heater.

They're kinda expensive... Lowes

I may be wrong but I think the tankless Gas water eaters use electricity for the ignitor. If thats the case if you lose power you have no hot water. Mine blew up the day before Thanksgiving and like others have said they have gotten expensive.
If your on Alabama Power you could always go down to the local office and tell them you want to switch to electric and they may give you one for free.

If you live alone, you may not use enough hot water to recover the higher costs.

I would think living alone would be the perfect scenario for on-demand water heaters. That way you're only heating water when you need it, instead of heating water all the time that rarely gets used.

You are correct

Love mine. It's a Noritz