eBay

eBay didn’t charge a fee on shipping and the last time I bought something, they didn’t charge me a fee on the tax.

in the past, you would see a widget for sale on the cheap but the shipping was 10x more than what it actually cost to ship.

@8th-note  nailed it btw....

Paying around 15% or so to achieve an honest auction value for an item is a much better alternative in my experience.  

At the end of any day, eBay is a 24/7/365.25 auction at its' core.

As is Audio Mart, and the plethora of others for that which boats your float...;)

And shipping frequently becomes Your Problem.

15% is the price of admission to their vast buying audience and site logistics.  Seems fair enough to me.  I have bought and sold a lot of Tubes (best site to sell on) , CD’s and LP’s  with great success on eBay.  Higher priced items like components I sell on another site to avoid the high fees.  

OP, have you talked to eBay?

Yes, I have talked with eBay and all they say is this is what they charge. No real explanation, other than that.