While I agree that eBay fees and particularly postage hikes don't help we are talking about DVDs and CDs which come under media and if you have a store BIN listing fees after freebies are used are only 5c not 20c and can generally be posted at letter rate either $1.20 or $1.80.  unrepentantly Auspost will increase these shortly but at the moment they are OK.  eBay don't want auctions and their pricing reflects that, so you may need to consider a store.

Many of the regulars keep talking about the death of DVD and BLR but like TV which never actually caused the death of cinema and while CDs mostly replaced Vinyl they still has a strong niche market and are making a come back, so it may be quite a while before streaming replaces DVDs/BLRs.  People still like things that are tangible that they can hold and play.  Also for audiophiles BLR has lossless audio with many movies in 7.1 audio, something that streaming services don't yet offer.