My biggest worry...do you trust that if you have a problem with the Costco spa (Highlife) you just call up Costco and they're going to have someone there to answer any questions or any problems you might have.
Also if they do have someone to service it...are they factory trained or a random service man.
I understand the upfront savings of money but will it mean anything to you in the long run.
It kind of reminds me of Thermospas...no dealer service and POSSIBLE service nightmares
My only thoughts...good luck