How do online sellers A/B test their prices today?
Many discounts out there (e.g. abandoned carts, secret sale) are like unorganized price A/B tests.
Example: you're selling $100 shoes and have a 10% off coupon which could be applied for $90 after discount. This is similar to a price A/B test of $100 and $90, but you aren't splitting your visitors into 2 equal groups.
Big companies like Amazon, Walmart, Target, Best Buy also do dynamic pricing and discounts.