There's one important factor this experiment is not controlling for: inventory. If user A gets deep enough into the purchase flow, the hotel will place a hold o

There's one important factor this experiment is not controlling for: inventory. If user A gets deep enough into the purchase flow, the hotel will place a hold on their room for 10 or so minutes, and that room will not be available when user B does a search. If pricing is dynamic, and for these hotels it obviously is, user B may well be shown a higher price regardless of geography. This applies even if the experimenter is not going any further than checking top level prices, because other people are booking actual hotels and thus impacting prices all the time.