gas heaters /solar

ok was thinking of getting a small gas heater on lpg
saw something that said that gas heaters use a lot of gas ie a lge cyclinder every month if the heater is used a fair bit ?
can any one that has one possiblely tell me how they go gas wise and what the mj thing is in the sale blurds

am also interested in the gas instant hot water systems as well for a one person household would the gas instant hot water be a better deal than the lge electric off peak that i have would like solar but is so expensive

and a totally different ?

if i had a home built solar hot water ( have been thinking of this for yrs ) ( a old grass roots magazine fan ) and had the gas as a booster if the water is hot going into gas heater it would still ignite or dose it not work that way ?

and the last question can you buy those water filled raditors ( like they have in england ) in aust ?

LPG heaters cost heaps to run.
The hot water units are ok, the instant ones probably ideal for you.
I think you can turn the auto ignition off, I'll look at mine next time I'm at the house.
Reckon you could use a car radiator (or car heater core) if you didn't run at a high pressure.