Pretty much, although those prices vary wildly depending on season, how many ships are in port, which ships, etc.
Extreme example...
An OTW cabana is only $1499 on my Indy cruise next month (which is quite low nowadays). We're the only ship scheduled to be there right now.
On my June 2023 Wonder cruise (also only ship there), it's $3799!
Not sure what type of cabana you're hoping to reserve, but regardless, I don't think they sell out as quickly as it seems you believe. If you're keeping an eye out, you should be able to get one.