The unfortumate fact of
Lego is that they release then discontinue sets. The moment they are discontinued, their value skyrockets. Great if you have extra to sell, not so great if you have a child that just got into it.
Looks like the only set that was released in 2017 was Silent Mary, with a price of 199.99. (
http://lego.wikia.com/wiki/Pirates_of_the_Caribbean_) It seems to still be available.
Honestly, if your state's sales tax is lower than CA's, and if you don't have an AP to get a discount on it, I would buy it from the Lego website (
https://shop.lego.com/en-US/Silent-Mary-71042) instead of while on your trip. Legos have a tendency to be lost, and kids have a tendency to want to build NOW; and that's a bad combo while at a hotel, take it from me.
I don't know how old your son is or how long he's been into legos, but that set has an age recommendation of 14+. I wrote into Lego once about their ages, and they said that age recommendations like that are all about frustration level (once you're past the Lego-swallowing/inhaling age) So if he's a Lego expert then go for it, but if he's not, expect a complicated build and lots of helping him. Of course, if he's an expert than you know all this about Legos being discontinued.