You will get many suggestions but here ismine.
I would creat a separate collection for your traders (duplicates) and add them directly in there. You can do so by using the option of "Update your For Sale / Trade list". They will automatically go green or "For Trade". In your other collection, you can then add the cards you have and the wants. If you have almost the whole set as you describe, your method is one way. If you don't have a substantial amount, you can use the drop down feature of any card to "Add from here to" which will then direct you to the list of collow on cards. You then select the series of cards you have and click there entering all those cards into your set.
The use of multiple collections is a good choice for most of us. If you plan to trade here, keeping your Main Collection empty helps as when you receive the cards in trade, they automatically go there and then you can direct them to whatever colelcction you wish.
But as I said, you will get many ideas here in this thread. You can also look at the Collections of those who post from their profile page, and see how they have done theirs.
Bruno
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Check my Profile page to see my 2023 Goals and my Lists of sets near completion (5 cards or less) or sets getting close (less than 100 cards missing and 75% complete).
https://www.tcdb.com/Forum.cfm/Page/B/ID/0/?MODE=VIEW&ThreadID=25745&C=0