Why were prices 'slightly higher west of the Rockies'

Looking at old clothing ads, I see that all the time and always wondered why. Something to do with the cost of shipping? A thing of the past now that clothes are mostly made and imported from China?

Exactly. Most of the clothing manufacturers were in the East or South, so they built shipping costs into their business model and ads. Just like today when you can find ads that say “prices good for the Continental US. Prices higher in Alaska/Hawaii.”

Thought so! Thanks!

Does this sort of thing happen elsewhere in the world? For example, do Norwegian ads sometimes say that prices are slightly higher in Svalbard? Do Argentinian ads say that prices are higher in Tierra del Fuego?

Don’t know about those, but in the UK, prices are often higher (or at least shipping for mail order is) for Highlands and Islands. Many offers on TV have “not available in N Ireland, The Isle of Man or Scottish Islands” in small print.

Still in the UK, even the Post Office, which has uniform pricing rates within the UK, changes it’s terms for more remote areas (and some not so remote). I regularly use their ‘Express 48’ service to send stuff from Edinburgh to Newtonmore, which is only 110 miles north on the main road to Inverness, and the terms are adjusted for that area and beyond, allowing them an extra day to deliver the parcels.
They often do arrive within the 48 hours, but not always.