In order to support another hobby, I'm in the process of downsizing and finding new homes for a number of safe-queens. That includes three of the five JDI imported Swiss SIGs I've purchased over the last seven years. A little over a week ago, I sold my PE90 (550) and my 16" 551. They were listed on another forum for $4,000 plus shipping, and I had buyers within a day. Both are unfired and included a Swiss stock.
I also listed an unfired Swiss SIG 553R (7.62x39) for the same price, but I haven't had any offers on that one yet.
In a perfect world, I would have a 1500 sqft home armory and plenty of extra money for all of my hobbies. However in the real world, storage space and hobby money is finite, so I have to be realistic about the number of safe-queens I keep. And honestly, when I'm dead and buried, a large, expensive gun collection will be a burden for the wife to deal with.
Like you, I will be keeping two Swiss SIGs: a 551 LB and a 553 SB. As cool as they are, I didn't lose any sleep selling the PE90 and the 16" 551, and I won't lose any sleep when the 553R sells. I'm not dwelling on the fact that they (and other cool guns) are gone. I'm focusing on the car I'll be buying with the proceeds.