I think the rust is excessive, and that it will be impossible to raise the car using a floor jack as a result. And of course, rust never sleeps. It gets worse as time progresses.
You didn’t say how much money they are asking for this car. If they are asking $2000 or less, and it has decent tires and will pass emissions, it might make sense to buy, knowing that this will be a short-term vehicle, which will likely only last another 1-2 years. More than that? Try to contain your laughter as you walk away from the “deal”.