eBay secretly over charged sellers

@donvito - like a lot of people, I post here and sell
on USAuduomart - you keeping tabs?

eBay, as mentioned by one of the other posters, is the biggest game in town with the most exposure for your item. That's what you pay for when you go there, otherwise start your own auction website and pay what you want. Buenos suerte.
In reality, if you're a seller on eBay, you know what a particularly tone deaf organization they are for their sellers. Most of the changes that have taken place over the last 20 years haven't been beneficial for sellers and as a result you saw a visible drop in quality sellers. Bottom line is they don't seem to care if you stay or go and they continue to hand their paying sellers off to offshore customer service reps who barely understand the language. Good luck with that, I've been selling elsewhere since the PayPal split.

There is still one good thing about eBay - their Global Shipping Program. I have yet to find a similar reasonably priced, convenient to both seller and buyer, service to get bulky items shipped from US to Europe. I have successfully purchased an AVR, subwoofer and floorstand-speakers. All other shipping options - USPS, DHL, UPS - were priced way too high.
Thanks to eBay GSP the transaction became at least half reasonable.

eBay are cheap!!

Christies, Sothebys, Bonhams and most other auction houses charge the buyer 25%+ taxes plus another 8%+ taxes to the seller.  Here in Europe the taxes are typically 20% of the charges.

They turn over billions.