Welcome to our forum.
The good thing about the costco deal was they thre in the Ozonator but on a small spa not such a big deal.
The reason its not a big deal IMO is having an ozonator can vary from getting a high quality CD unit that is pretty much maintenance free to getting a cheap (quality and cost) UV type that requires a bulb change every 18 months where the cost of the bulb is about equal to the cost of the unit and I'm guessing here the one they're including is the latter. I wouldn’t give any real weight to the ozonoator being included. A friend of mine who I don't see/hear from often got a spa last year (without checking with me first). When I went and checked it out one of the first things I did was take away the crappy ozonator he had and gave him a real one. Some of them should come with "Fisher Price" stamped on the side.
So does the Jacuzzi J-470 come with a good ozonator?
Ask what ozonator is included in the package he's offering and then ask what other options there may be available. Often they have multiple types and it wouldn't be the first case of someone "throwing in" a cheapo one to satisfy the statement that the "ozonator is included at no additional cost".
And, there are many cheaper after market ozonators that can be installed by a dealer. :-/