we sold three vehicles (yukon and two tahoes) to dealers over the past few years. last one was fall of 22.
got prices from carvana, givemethevin, carmax (they were competitive but closest one is 3hrs away), kbb (which really isn't kbb - they have dealers in your area that are associated with KBB that'll give you an offer) and then several larger dealerships. just a matter of plugging in the info online for all of them and bam - an offer. the dealership route was the same process....just find a few dealers in your area that you'd think would be competitive and they should have a place on their website where you can enter your vehicle's info. 20 mins of your time and you'll have 5+ offers
sold all three to different dealers, one was a large KIA dealer that had a high end used lot - came out of the KBB quote, one was the local ford store (stopped by and talked with them) and the other ended up being a large pre-owned dealer.
on our recent purchases we just traded this past year - did compare with several online quotes and just used them as comps for the trade in values (....said if they'll match this offer we'll do the deal type of thing).
The sales tax credit allowance when trading is probably going to eat up any profit when not trading, unless your state allows for private sales to also offset a purchase. Using a tool like
Credit Karma might help you understand your state’s tax rules. it's worth a couple mins searching online to see if your state does.
here's my state's guidelines...