When I wrote https://lackhand.wordpress.com/2015/05/27/5e-long-rests/ , I overlooked the obvious.
The costs I listed are a bit nuts. Instead: To repair gear, you must be living at a lifestyle level for the 30 days preceding it commensurate with the broken gear.
- Artifact: Aristocratic (50gp/day)
- Legendary: Aristocratic (25gp/day)
- Very rare: Aristocratic (10gp/day)
- Rare: Wealthy (4gp)
- Uncommon: Comfortable (2gp)
- Common: Modest (1gp)
- Mundane: Poor (2sp)