Looking at several used units, most are 10-20 years old in the $500-$1500 range. I am kinda interested in this one unit a Energen 190,000 btu unit. Cant find any info online, assuming the company is outa business, anyone ever hear of or have one? It has a 36dx28hx22 w firebox, it's top loading, it's 20 years old, BUT, NEVER been fired ,brand new. But will this thing eat my firewood like it's goin outa style, is it a waste, basically saving money upfront but using it up in firewood as opposed to saving up for a more efficient unit, or is it possible a unit with 20 year old technology could possibly be efficient?