Here in the south bay I don't have InstaCart, but my local Safeway does deliver.
The experience isn't the best (someone has to be there and sign) but a) I have a nanny and b) I don't pay $299 or 14% more for the items.. in fact, I would pay less as I don't carry a loyalty card, but deliveries give you the loyalty price (presumably, they collect the same kind of info anyway).