Seeing as how a commercial gas range comprised of four 25,000 btu burners and an oven of usually 30,000 btus goes for $2,000, I am pretty darn ticked off with the prices on residential gas models. True. the commercial models have less fire insulation, but are constructed bomb-proof and have much more powerfull burners.
A residential unit should not have 25,000 btu burner becasue most households don't have commercial hvac systems or fire supression systems, or 2 hr rated fire walls for this kind of power. Nor do they have "1 lb" gas lines required to feed gas to such a beast.
So why do the residential units cost waaay more than the commercial ones?
I dunno, Why do bullies pick on little kids, why do dogs lick their, uh... privates?
Answer: Because they can.
If you want to buy a residential gas oven and range you need:
-Cast iron burners. Not stamped tin ones made from re-cycled beer cans
-Cast iron burner grates/grids. DO NOT tolerate porcelainized grates. It will scorch and burn/flake off and discolour within a few months.
-S/s or cast iron surface under the burners. Again, DO NOT tolerate porcelainized surfaces.
-That being said, porcelainized oven cavities are just fine, as they are not subject to naked flame. S/s oven cavitites are usually very thin guage and will buckle and warp and invariabley get heat-stained anyway.
-For the money it should have a heavier guage (16 or 18 guage) s/s skin around the "showing" surfaces.
If they brag about convection ovens, it should be a "True convection". That is, a fire box under the oven floor with a fan drawing in hot air and blowing it into the oven cavity, NOT a fan at the back of the oven added as an afterthought kinda/sorta blowing warm air around.
Best thing to do is to really study mnfctr's websites and sales literature. Believe it or not, Sears usually has some decent ovens in the $1800 and up range
Stay away from the fancier electronic controls. These usually "Go" after the 1 year warranty period.
Hope this helps