Well, no regrets here. Yes, it's overpriced. We got the Standard Package (50 euros) and it included an algae face mask, one drink, a towel/robe and skin care pack. But not too crowded, the pool area is big and they have enough changing rooms, lockers, etc. to accommodate a huge crowd. We bought our tickets ahead of time as part of our airport shuttle, Reykjavik Excursions.The grounds also have an area where you can store your luggage for cheap.
We arrived at the airport, stressed out to the max from almost not being able to come back to Iceland from Amsterdam because of the infamous volcano, so we made this our first stop. Best decision ever. It was relaxing and a really unique experience. The staff was so friendly! The milky blue water made my skin feel amazing (my hair, not so much. Bring conditioner!) and the landscape around the pool area made us feel like we were on the moon. It's worth it! Stop by when you're in Iceland, to or from the airport. It's a little splurge that will make you feel like a million bucks. Once we were done, we jumped on the next FlyBus to Reykjavik (about 35 minutes) and our Airbnb hosts picked us up from the bus station. The perfect start to our trip.