Question : Is Paris Orly Airport (ORY) the cheapest airport for getting to EuroAirport Swiss (BSL)?
Answer : Departing from Paris Orly Airport is not the only way to get to EuroAirport Swiss. Try looking for flights from Charles de Gaulle Airport (CDG) as well. Over the upcoming months, flights from CDG to BSL are being priced 62% cheaper than flights from ORY to BSL. Being only 21 miles away, it's easily accessible for most.
Question : How long do most people stay in Basel, Switzerland?
Answer : Of course you're not most people, but if you were, you'd stay roughly two days.