jmartkdr2
Hero
Although we should let this thread die,The fictitious 5e D&D economy is wild, resembling neither a medieval economy nor a modern one.
For practical purposes, the cost equivalence of a gp seems roughly anywhere from $5 to $25.
1 gp ≈ $5 to $25
Compare handforged combat worthy longsword:
15 gp ≈ $400
1 gp ≈ $26.67
Compare handforged combat worthy renaissance full armor
1500 gp ≈ $7000
1 gp ≈ $4.67
Personally, for the D&D economy, I suspect the 1 gp per $25, to be the more useful approximation.
One thing to keep in mind is that this is pre-industrial (unless it's Eberron or something). All things are hand made, there are no cheap disposable products other than food and stuff that comes fully formed in nature.
So use handmade prices for everything and 1 gp is about $10 (in my area) seems to work well enough.