These days, most appliance manufacturers, do a poor job of keeping replacement parts in production and inventoried past just a few years after discontinuing an appliance model, if that much. However, Subzero is one of the last standing that actually keep parts on hand for much older models. So, with a Subzero, you should not have to worry about parts access for a very long time down the road. When it comes to features, you’ll have to compare between the old and the new, but it’s hard to imagine anything earth shattering that they’ve introduced in their new line of refrigerators that would be worth $2000, but again, When it comes to features, it’s very subjective in terms of what you may want or not care about.
You are correct that the MSRP of brand new Subzeros is not negotiable , but you might have at least some additional wiggle room on the price if it is a floor model. All the best on your decision.
Q