Balloon Fly in Budapest

We did Balloon Fly in September. It was a neat experience but not one I would do every time I'm in Budapest.
It provides a different perspective of the city, which was interesting.

Once you've boarded, you'll stay in one spot for the duration. It's about 5 minutes to the 'top,' and another 5 minutes for observation, and then 5 minutes to get back down. It has a slight sway but nothing traumatizing.

Did you make a previous reservation or just show up? Was there a waiting line? We are going late April perhaps on Tuesday

We just walked up to the booth and purchased tickets and boarded the next session.

Do they accept euros?

They only advertise in Forints; but its not inconceivable that they will give you a sort of padded price in Euro to sell a ticket. But you really should be wandering around with a little local currency in your pocket. Visit an ATM. At 8.500 ft per ticket, sort of pricy. Go and report back.

There is no advance purchase right now, and I would not count on a credit card machine (but dont really know)

It's 8500HUF now? We paid 7000 in September.

We paid with card and Euros were not an option.