Ebay will take over and control your life if you let it. The trick (and the difficult part) is to control it...
Obviously most posters here prefer auctions, but in the days when I sold (I no longer do) I went with Buy It Now sales. Profit was never my motive, rather my goals were to clear the mountains of photo gear I accumulated over three decades and free up space at home. Yes, sure, the spare cash was great to have, but for me it was just that, spare cash.
Use the Advanced option in Ebay and check for recent sales. Not just the first sale, but as many of them as you can find - check what prices were paid and read the descriptions to note how they were worded.
Ideally, set yourself a reasonable goal and stay with it - like no items over $100, $150 or $200.
If selling cameras, be particularly careful - you will surely get at least one case of 'buyer's remorse' who will then try to fabricate a complaint to get their money back, as well as the time-old trick of trying for a refund AND keeping the item.
Watch your descriptions!! For example, many sellers say something like 'sold as is, no returns' but then go on to add 'returned items at buyer's expense' which sends a mixed message. Be cautious in your wording. Don't over-inform. Avoid verbiage. Err on the side of brevity. Stay positive. Avoid empty praise words ('minty' is my pet hate but 'mint' 'vintage' and 'rare' are also three that truly irk me) and stay away from puff like the following three I read recently on Ebay - "speeds all work well except 1 second to 1/15 when the shutter stays open" "this can be repaired cheaply" and "the lens has some separation but this won't show in the images". Sure as anything these will result in buyer complaints and I reckon well deserved they are too!!
Try to avoid selling expensive camera gear on Ebay if you can. After two bad experiences with dishonest buyers in 2018 and 2019, which involved me in no end of discussion with Ebay until I was able to get the items returned by the buyers, I saw the light and I now sell good cameras on consignment with a reputable dealer in Melbourne. The commission I pay is 25% and at times I get less back than I could have with Ebay - here again, comparing sale prices in posted ads and in finished sales on Ebay will be both revealing and educating - but the potential headaches I avoid by going with shop sales are, for me, worth more than the cash value.
We live and we learn. We all need a certain amount of aggravation to keep us functioning in life, but for me Ebay was too hard going.