Hello, GTB, fellow completist,
(altough I can only compete in the SSW statues and environments section and the SS PF and diorama section...)
You are one of only a handful collectors in the world that have been able to get all of these items into your collection. I am sure you have enjoyed the time and effort spent to get it together and it would be sad to see such a collection to be sold and split up.
I don't think you'll ever be able to find anybody that would buy the collection en-bloc and promise you to keep it together. Somebody that would be interested (and have the funds) will most likely already own some of the pieces and would not want to have doubles.
As previous posters have said, your only chance to get some / all your money spent back is to sell all the pieces individually.
The only price tag I could put onto your collection would be the SSW part - but you should be able to get that value from Toytracker, which should be a good indicator.
If your buying price was in Singapore Dollars, keep in mind where the US Dollar is at the moment and maybe wait a moment to see if the US currency is gonna crash completely or not...
Whichever way you and your collection will go - keep us updated!