Fair points. I agree entirely that the cost of travel, airfare and gasoline primarily, would skyrocket in the lead up to the yearly Purge. This would probably also be the case for a lot of other goods and materials (food, water, weapons, ammunition, batteries, etc), not unlike an impending natural disaster. This would certainly hit the lowest income people the hardest.
I do take issue with the last point though. I don’t think it’s a fair comparison to refugees or to call them “Purge escapees”. The wealthy people who would be able to schedule a vacation for the Purge wouldn’t be leaving the country forever; they’d return within a few days. I could see some countries taking a moral stance and banning travel from the US into their country, but there would be some countries which would remain open. One could even picture a scenario where the US Government, who obviously support the Purge and allow it to continue, would make a diplomatic arrangement to ensure that the wealthiest US citizens had somewhere to go.
Sorry, this is becoming an increasingly unenjoyable thought experiment. I’m going to stop there.