Pheryll
Set Designer
Take a look at the Travelling merchant that you can now make in crafting.
When they were first released they had the same price. Only after I mockingly called them out on their 16:4:1 ratio regarding them did they tweak it, and still the TM3 costs 1.4x the TM1 .
The traveling merchant is nowhere close to the high production of the set buildings. And disenchanting a building into fragments is the same cost per square, whether it be tier 3 goods, tier 1 goods, or a magic residence. Look at the winter market set. The ratio for those productions per square are 1.19 : 1.11 : 1. Given the way building costs are going every three guest race chapters, it wouldn't surprise me if the manufactories are headed towards an almost even 1:1:1 ratio as well.