never done a day bed, but with a cabana you get a personal waiter to place orders with for food/drink, but that's about it. the food/drink is extra. sometimes the cost of the cabana/day bed goes towards F&B costs.
I know when you purchase a daybed at Liquid it costs somewhere between $100 - $200 (if I remember correctly), and you get an F&B credit in that amount to spend. To me this reward clearly isn't worth the 500k points since it's not even a cabana and the day beds themselves aren't THAT expensive!
A cabana is priced $250-$300 mid-week and $350-400 during a regular weekend @Aria. Then F&B are available at an additional cost except for soft drinks and water that is complimentary. I dont know what day were you were at liquid but usually the prices goes from 500 and up to over 2k for a daybed and even more for cabanas. In dayclubs its the norm that you can use that cost towards F&B its just a minimum spend.
For the same price, you could do the complimentary table and bottle service at Haze, which to me would seem to be a better value
Also, despite it changing, it states its only available until 5/31, so you would need to be visiting soon to make use of the day bed
500K seems a bit much there has to be something included with it I mean you can have a 3 night stay for less than that (165K x3)
Pretty confident it was nowhere near $500, but that may have been on a weekday. It was also 2 years ago, so the prices may have increased.