Base durability is fine.
Durability from experimentation could use a buff. People shouldn't feel like skipping out of one point on another stat for dura is a waste of time. It should be a compelling option as something other than a dump stat, and for that to happen each experiment point of dura needs to be worth more.
Stats vs. damage on weapons for instance is often a compelling choice for which there is no obvious "best" but literally any stat vs. durability is never a compelling choice at the moment because the durability added doesn't last long enough to make getting a less performant item worth it.
If experimenting on durability added significantly more than it does now, building that max durability weapon with only half as many pips in damage might actually be attractive. Currently its such a low amount that it isn't.
This would also be a huge boon to skilled crafting accounts as their maxed out low tier items would be of significantly more value due to the radically enhanced durability. if you can get two identical green breastplates but one of them lasts three times as long, you're going to seriously consider paying more for that items even if its functionally otherwise identical. You may actually have a tough choice between that item and the marginally better blue breastplate that's only going to last a third as long for your money. Currently no amount of durability experimentation feels significant, and it competes with too many high value experimentation vectors to be worth it at that level.
I propose halving the point max for durability rolls and radically increasing their value. The halved max would prevent the durability values from getting too out of line while making dipping in to durability feel like a valuable choice for all skill levels of crafter and all rarity ranks of item.
Treat it like other "off-race" buffs and put it on a major. Making people take illusionist for camo if they're not a wood elf or Arcane archer for OOC move speed if they're a slow race is fine and balanced.
Putting +stealth move speed on, say, Agent Provocateur or something would be balanced just fine. Play fae and get the speed without a major, or play another race and take a major for it if you want it.