I'd say just get quotes from all three if you can. Give Me the VIN needs photos, Carmax usually takes 30 minutes to an hour, and TDA will probably take some time too.
It comes down to convenience and how much you really want to get for your vehicle. If that few hundred dollars is worth the effort to you.
I responded with basically the max blue/black book +1k. they came back with a 1500 lower offer which i took to a dealership and they matched it. Got a little sales tax credit and called it the day.
they low ball the first offer and you can haggle up to about carmax. TDA usually beats him. The guy is kind of a dick and tries to pressure u into selling. Send him ur vin, tell him to **** off when he lowballs, and he might come up near carmax or slightly higher....or just save yourself some time and take your car to tda and sell it outright.
Used them to sell my truck out of Midland. They came in about 1k less than KBB - I told them to make it KBB + $1k and we have a deal. They took it. Came and picked it up two days later, check in hand and everything.