Year 2010 there was situation where Rigol send warning letter about "counterfeit" or some other kind of illegal sales in eBay. Result was that nearly all DS1052E disappear from eBay.
I have not possible at this time for find more documentations, including one public warning letter from Rigol.
But here in forum I find something
https://www.eevblog.com/forum/beginners/ds1052e-removed-from-ebay/It was also some amount different case. These was new units and lot of listings was stopped and if I remember right even some eBay accounts perhaps closed. At this time it looks like Rigol use "brute force" to eBay and I do not know how they did it.
----------
But here, OP, sell his second hand SDG just as he have also sold his used 4 channel SDS1xxxCFL.
There is not any reason in this case. Everyone can sell his own used equipments what ever price. No one can deny it or blame.
Very clearly this is some kind of mistake from Siglent and after I read this whole thread my opinion is that Siglent need do something more now for real apologize this terrible case. Also in eBay listing read cleary it was used and condition is mint.
Also I. as Seiglent seller, can sell used Siglent equipment if I have one and I can sell it what ever price I want.
I'm seller but also I'm user. I do lot of electronic things and here is also equipments from my own use, independent of name, HP, Tektronix, R&S, Rigol, Owon, Siglent in my own use. Just after I look I need sell them as used and invest to some new equipment what I need, I will sell these and no one can stop it what ever price I ask.
Selling new equipments, it is bit different.We can never do work for even low level support if we do not get any salary for this work. Handling warranty cases, for doing sellers own quality control and even keep some kind of pre- and after sales product support for potential customers and of course always for customers who have purchased. If some one need help just for "how to use" equipment in some special case. This work is not free but is funded By collecting small slice for it from from every unit selling price.
This is why "carton shipper sellers" are different and they are ones who destroy whole product support pushing prices so down that there is not room for any extra work but just receive money from customer and do shipping.
Take example. In stock there is factory made equipment but after then there have new FW. Do I sell equipment with old FW. Mainstream no. During quality control tests I will mostly also take care about FW. Specially if theere have been some bad issues with some FW and if end user do update he may go to problem like as "fun" as upside down display or something like it. For avoid this quality seller need also take some care about these and update FW himself (specially if there is kown issue with some HW) for avoid end user problems as much as possible. But all understand there is not free lounges.
Be free to sell your second hand Siglent.
Btw, also I have one used SDG5082 for sell but only in Finland.
Really, Siglent, we do not want ANY this kind of hassle!