$3.70 adjusted for inflation is $5.11.

A double double now costs $6.35-$6.50 (depending on your location)

TempleOS is at the bottom left, at the margin

I can imagine price stickers would update daily, and individual users would get personalized discounts on their app.

App-less buyers would pay the baseline price in the sticker, app users would pay less. Like existing loyalty card programs, but with more data collection

Canadal