They tend to offer competitive pricing but it's a pain otherwise.
I sold my 15" 2018 model for $1400 on Ebay after being offered $1410 on trade-in. The reason I didn't trade it in was because I was selling two laptops to buy one (16" MBP) and if I had traded those in I'd have been without a computer while waiting for them to send me the trade-in shipping container, then I ship it, wait for them to get it, analyze it, then ship me gift cards. What kind of turn-around are we talking about here? Sounds to me like a good two weeks if not more. I sold my two laptops on eBay for very close to the trade-in Apple was offering (one right at, the other for $75 more) and got my money, all within about 48 hours and right after I shipped them both our I went and bought the MBP 16".
If you put it on eBay, you will get action all day long. There's a LOT of customers who are looking for these. Apple products fly off the shelves on eBay. I haven't had to wait more than a few hours to sell any iPhone I've ever listed. One of the computers I was listing sold in 5 hours, the other took 24 hours.