If you're a high enough level, you can get barrows armour quite easily from barrows itself. It's easy to get, thus being not that expensive, but probably the best armour around! Magic and range both have to use up money just by attacking (moreso for magic), and melee has to have some type of drawback, especially for amazing armour, and at a low base cost.

It's not horrible they degrade. At my level I can make easily slayer with it and than make a profit back from it. Of course if I had the money for Bandos I would buy it but for now I'll stick with Torag's: Great defense and pretty cheap. I mean like I had 2 Gargoyles tasks and 2 Terrorbird tasks and I made like 500k profit (minus the repair wich was only like 100k total). This is in view hours so it isn't bad.