Trade-in will be deducted from the total sale price to reduce sale tax which is close to 7%. Private sale is too much hassle for me.
in that case, the strategy tree is easier to move forward. You should already know the price of the new Ascent from the dealership. You seperately negotiate a trade in price for your existing vehicle at the dealership and compare that with offers from the other buyers such as Carmax, other dealerships, etc. If the net cost from the dealership after deducting the 7% is less than the net going through Carmax et al. than use the dealership. I just went through this when I sold my 2019 Ascent Limited and bought my 2023 Limited. Despite the dealership's slightly lower trade in value they offered, the tax benefits netted me more to reduce the overall cost of the new purchase. In addition, there was the added benefit of convenience to complete the entire transaction in one day at the dealership. I ended up saving $$. I not only had explored the selling of my 2019 to Carmax etc, but also to other Subaru dealerships that I was not going to buy the new Ascent through (the dealership I bought the 23' from had no dealer fees). I was able to bring up the other dealerships' used vehicle offers, but not sufficient to offset the tax savings. My purchase price for my 23' was fixed through the VIP program as was the financing at Subaru/Chase lowest rates.