If I’m buying a dyson, should I buy the vacuum from costco/samsclub or from the actual online store?

We had a dirt devil canister which was the worst vacuum ever ..now I’m really thinking of something durable and never lose its suction power and no more bags to buy ,we went to Costco and a sales lady there told us about the dyson one -it’s really expensive around 0.
We have a small house and two kids ,I was thinking the canister will be easier to hold it up and down the stairs than the upright models ..we have carpet and bare floors areas ..

any ideas?