This is my least favorite part about Tesla buying experience. I've been through that twice myself. When considering selling privately vs. trade-in don't forget to account for possible sales tax credit if it applies in your state (it does in many stares). As far as delaying the trade-in, Tesla gives you a price guarantee of x days, after that it gets re-evaluated. When I was trading my older MS in for a new one, I had the same problem (actually price dropped over the first 3 days by $2K which annoyed me), so I didn't want to wait weeks to find out what it would cost me.