>>9655881Ah, that's a little sad to me, I specifically look for listings with boxes and am willing to pay a premium. For example, if you had the box for that sphinx set, I'd actually be interested in it rather than totally ignoring. I've seen hundreds sold, and a box only pops up once every few years, same goes for most anything from the 90's or older.
Ebay is good for a quick buck with high fees, BL is better for the long haul. You can set a price and forget it. If you are patient, it can be way more lucrative, just depends on how desperate you are for cash.
I've been buying and selling LEGO actively for over a decade so I have a cache of boxes to reuse, it only becomes a real problem once you get into 2ft + dimensions, and even then, I just re-use the same boxes TLG sent to me. You are right though, it is certainly costly and not optimal.
As far as ebay fees go, if you are feeling scammed, you should try Bricklink. They only charge 3-5% fees and you have more control over your store setup and how you charge for shipping. I'm more likely to shill for BL as it's how I've sustainably made sales similar to your 90 day total there for years on end.
Take care, and don't feel bad for selling things, it just means you have money to buy more lego if that's what you're into.