So its free to list, no seller fees to sell (buyer protection fee paid by buyer instead now which actually works way better) and ebay simple delivery means providing you select royal mail as the option and not Evri, all that is handled too so you just take the qr code to the post office and its sent tracked 48 or 24 if the buyer chooses express.
Ebay deal with the insurance.
The simple delivery pricing on tracked is way cheaper than you can buy normally and as it's royal mail tracked then parcel size/weight covers all lego options. Just don't offer Evri as an option for your own sanity and delivery tracking/reliability.
You can also select large parcel and custom to choose your own courier. When they rolled out the changes in the summer this took a while to function as intended.
Ebay manage payments now and as a private seller depending on your seller performance you can withdraw next day and for me transfer to bank is instant.
Because of simple delivery, you dont incur costs as if seller pays it's auto transaction. You can post right away although the money won't necessarily increase your withdrawal Ebay balance until 1-3 days later depending on seller performance.
Having sold a fair bit on eBay (£1000's) from my collection (Lego plus other vintage to modern action / toy genres) the latest changes have been a great improvement. Especially simple delivery and managed payments so no issues of PayPal charge backs against you etc.
Just make sure you select royal mail as the delivery option and don't allow Evri.
Price the lego well and you normally sell very quickly and if the cheapest will hit Google shopping pages through the seo.