I would get a quote from a auto repair shop on how much it would cost to replace the interior with alcantara. Get it in writing. Start with that price when negotiating. If they quote $1200, ask for 2 years of service. If they say $1800, ask for 3. And it depends how much you wanted the alcantara. If you really wanted it, ask for more. Mine came with it, so I don't know how I'd feel.
I was promised the alcantara retrofit earlier in the week also by my delivery specialist and the Ownership Team and kept waiting for service to contact me to schedule, which they never did. This morning I received an apologetic call from Ownership saying that the attempted retrofits this week were not going well and too hard to do, so they are not going to be able to offer this after all. As consolation, Peter initially offered me Tesla apparel, which I promptly declined. His 2nd offer was first year of service free ($600 credit applied to my pre-paid 4yr service plan). I'm still deciding and may see if I can get 2 or 3yrs. Has anyone else due for the alcantara retrofit been contacted or been offered anything different?