Just did the same search, about 1 minute apart, on Expedia for a hotel with the same dates, number of occupants and filter both in a window where I was logged into Expedia and an Incognito Chromium one and got wildly different results for many properties.
The price when logged in is almost triple! It's the same room, of which 3 are left, and they even give an extra day to cancel with the cheapest price. It allows me to purchase directly without logging in, so the lower price is maintained.
Now, this is one of the larger differences but some times, the logged in price was slightly lower than the incognito one, so going incognito does not seem to guarantee the best price. Perhaps there are other prices too, depending on referral links, ads, etc (There is an office supply store that gives almost 30% discount when coming via an ad but in that case, it is always consistent).
Notice that the address is the same but the phone number is different. Presumably so that agents know which pricing level callers are coming from.
How can one get Expedia to show its best price for hotels?