When I shop in Luna, I'll see armor that has 60+ resists, LRC and LMC (or some other attribute).
This armor will be on sale for 1 mil or more.
Where does this stuff come from? Does someone craft it then BRSK it or do they find it as loot then BSRK it?
You can't "then BRSK" ANYTHING.
You cannot ADD properties to an existing item with a runic.
You either find an item with the properties, then enhance with the appropriate leather/metal/wood (And only one of those, based on the skill needed to craft),
or
You craft straight out with the Runic tool (which adds the properties as you craft it).
A Tailor with GM Arms Lore can make the following with a barbed kit
Leather armor (15 resists)
+12 resists from being made with Barbed leather
+6 resists from exceptional
+5 resists to the exceptional bonus for GM Arms Lore (+8 on Siege)
= 38 resists, before Properties.
If the only two displayed properties are LRC & LMC (or LRC and one other property), then potentially there are up to THREE +resist properties applied. As each can be up to +15, that means an armor piece could go as high as
83 resists, plus two other properties. And, given the minimums for a Barbed kit (4 or 5 properties, 50% minimum), the WORST you'll see with only two displayed properties, is a total of either 52 or 54 resists (depending on which direction half of 15 is rounded) on a 4 property item, 59 or 62 resists if 5 properties were rolled (with only 2 displayed properties).
In fact, you can make items with 2 displayed properties and up to 68 resists (base 38 for exceptional with GM arms lore, + two +15 in one resist properties), with a HORNED RUNIC.