You can order two chairs ($42 x 2) and an umbrella ($31) on Amazon for about $115, and have them delivered to wherever you're staying on HH, and use them over and over. And walk to the bar to get your food and drinks.
It's my guess that they charge $65 because there are enough people (tourists) that will pay that much. It's capitalism, and if the folks at Tiki Hut can get people to cough up $65 for beach chairs and an umbrella, good for them. Nobody is being forced to pay it. It's a free market.
I mean, there are people that pay over $200 to change the color of the hair on their head. Me? I think that's completely nuts. But if a hair professional can get that much money from people for the service they provide, good for them. Go get it.
And, yes, the backward "3" is a stylization of an ampersand (&).