Cappadocia hot air balloon: how far in advance do I need to book?

Going to Cappadocia in mid May and the balloon ride is literally the reason for the trip. I’ve seen prices ranging from $150 to $400 per person and I can’t figure out what the difference is.

Do I need to book months ahead or can I sort it out when I get there? Some blog posts say book 2 months ahead, others say the hotel will arrange it the night before. Which companies are actually reputable? I don’t want the cheapest sketchy option but also don’t want to overpay for the same flight with a fancier website.