The way I make money is to kill monsters, make items out of the bars and dragonhides they drop and high alch the items I make out of them. I also high alch the metal items they drop.
It's not a fast way to make money, but I don't care. I fight monsters mostly for fun but yeah that's how I do it.
Ironman method of making money ^
Except you can't really sell valuable treasure trail rewards in ironman mode.
But for the most part you are right. Most of the valuable monster drops like dragon platelegs and abyssal whip are now worth the same as the high alchemy value.
But I'm sure I wouldn't be wearing my dragon platebody in ironman mode though.