Blue Wave Pool and Spa: $7.99 per month for the first year, then $6.99 for the second year, $3.99 a month for three years, $9.99 and $5.99 thereafter

Wave Pool: $9 a month per year, plus $7 per month per child for the next year, with no limit.

Photo: Instagram/billy_fitzgerald source Bloomberg article Blue Wave Clipart: $10 per month, plus up to $15 per month after one year.

Photo credit: Instagram user billy_friedman