I used to be bothered by this quite a bit.
But, although there are some items which are out of line with my expectations of what costs should be, they are few and far between.
My real problem lies with the wages that various hirelings get. So, I multiplied all wages by 5 in my game.
I use a 1 CP = $1 ratio and compare costs to real world equivalents (i.e. a horse is not a horse, it's a car or motorcycle since it provides transportation).
When NPC wages get multiplied by 5, the 1 SP guy only gets paid $50 a day (with my ratio). But, $50 a day makes a lot more sense to me than $10 a day.
This guy only makes $10K a year, but he is at the bottom of the totem pole and had better have roommates.
The yearly equivalent wages then become:
$100,000 Alchemist
$15,000 Animal tender/groom
$50,000 Architect/engineer
$100,000 Barrister
$40,000 Clerk
$10,000 Cook
$40,000 Entertainer/performer
$10,000 Laborer
$60,000 Limner
$10,000 Maid
$30,000 Mason/craftsman
$20,000 Mercenary
$40,000 Mercenary horseman
$60,000 Mercenary Leader
$10,000 Porter
$200,000 Sage
$30,000 Scribe
$40,000 Smith
$30,000 Teamster
$20,000 Valet/lackey
Are these real accurate? Probably not. But, most of them are in the $20,000 to $40,000 wages that a lot of people make in the real world (in the U.S).
So, this makes sense for me and my players since all of us live in the U.S.
The day laborer is paid the worse, but at 5 SP per day, he can still go into a bar and afford an ale at 4 CP once or twice a day.
This has resolved most of my problems with it and at least made it such that your typical workers can afford to be seen in the tavern or inn without saying that item costs are 2 to 10 times greater for adventurers (i.e. they see the tourists coming syndrome where any smart adventurer would give a local a SP to go buy a backpack at 5 SP instead of the adventurer's 2 GP price). YMMV.