eBay has no legal right to introduce anything like that when sellers are just trying to protect themselves from problematic/fraudulent buyers (which the sellers have the legal right to do) but eBay will get away with it for obvious reasons and sellers will whine about it as per usual and do nothing about it because they are clueless as to their legal rights. Businesses in particular using auction sites have government given rights that allow them to protect themselves from problematic buyers and this extends to the "official" websites of trading businesses as well, all new laws introduced in the early days of internet trading. This is just another example of eBay thinking it is bigger than the universe and above government law and just another example of eBay thinking it can trample all over sellers' government given rights. I could very easily contact an acquaintance of mine at Trading Standards and send a list of eBay policies to them for investigation and have the illegal 10% fee on shipping costs stopped (and that money refunded to sellers) but why should I? I do not trade on eBay anymore so it is not my problem hehe. The sellers there should band together and do it not me. Off the top of my head I can think of some policies eBay have introduced that have no legal standing at all and Trading Standards would force the removal of those policies in the blink of an eye if the sellers over there ever wake up, smelt the coffee and actually did something productive and complained to the right people about such policies and the total unfairness of things.
What astounds me most about sellers on eBay, especially the supposedly proper business sellers, is how little they actually know about their government given rights, laws and policies, and do nothing about eBay trampling all over those rights. It is probably because most "business" sellers on eBay are not proper businesses anyway (just hobbyists with a lot to sell and forced to register as a business by HMRC rules) so they have zero knowledge about their legal rights and just do not bother with reading up on their rights, the laws and policies in place because it requires actually reading something that will be tens of pages long when most of them cannot be bothered to read a single paragraph, and other actual proper business sellers have zero knowledge too because they could not be bothered to read the information they were sent when registering the business, start-up information which will contain varies websites for them to visit for reading up on law, policy etc, registering for VAT etc. never bothering to read legal documents properly, just glancing over things pretending they understand things when they do not and blindly signing it anyway, and eBay knows this, so they think they can do what they want as they know most sellers do not know their rights and they know most sellers will take no action against them, and you know what? eBay are right because what do the sellers do? Just sit around at their computers whining about this and that in the forums on eBay pretending they know it all when if they did actually know anything then they would not be letting eBay trample all over their government given rights! It just makes me laugh so much.
And I'm not going to go out of my way for these eBay sellers to do for them what they should do for themselves and report all these policies etc. to organisations like Trading Standards, the Minister for Business, Chamber of Commerce and so on - that's what these people are there for to protect and enforce your government given rights, give you guidance etc. and if needs be, take action against eBay to remove certain policies. But if no one complains to these organisations then they do not know a problem exists and eBay will continue to trample all over those government given rights that sellers do not know they have because they could not be bothered to do something as simple as "read" information that is there for their benefit and protection.