Dogs that carry their owner's bags

Two smart female golden retrievers, named Lila and Yama, are intelligent enough to help their owner carry her shopping bags, safeguard her purse, and can even tell whose phone is ringing among three or four mobile phones of Mrs Wu's family members, and immediately pass it to its owner.
Mrs Wu's clever pets always attract great attention due to their nimble movements, submissive and childlike behaviors when they follow their owner to the supermarket.
However, she commented that it costs her around $500 per month to raise her dogs, as they are fed with bottled milk every morning and have pig livers with rice daily. Sometimes, she even gets them some dog snacks from Japan!
She was offered $6,600 last year for Lila, but she declined the offer.