Collecting Dilemma X3 Questions!

For duplicates it really all depends what it is. If its something common I dont want anymore I sell it to get something I want.

As far as grading most of it is just a math game. Will the grading increase the value more than the cost. That cost will also vary depending on if its a throw in with another submission or it would be a group all by itself. Its cheaper as a throw in since the shipping costs are going to happen either way.

But if its a sentimental coin itll get added to a shipment just because I want it graded and protected and couldnt care less about whether or not it makes sense from a cost perspective

Alternative view.
For my slot fillers, I keep the one in best condition.
But for a year/mint VAM study, there is no such thing as a duplicate. I might have four examples of the same VAM. In addition to variances in grade, they can demonstrate the appearance or disappearance of some features. As the die wears, the doubling and clash marks may become less apparent. Die cracks and erosion may increase.
I believe it was Twohawks that related a story of a dealer that had a roll of Morgan dollars showing the progression of a grease strike through.

I can't really say about keeping duplicates as I haven't really bought any that were (unless you count random wheat pennies.) That being said I would probably hold coins on the chance of them being traded away. However, I would also be mindful of how much I have tied up in duplicates because that could be other coins for the collection!

I always hear $200 to $500 (depending on who you ask) is when a coin becomes valuable enough to slab. Basebal21 hit the nail on the head though. If your coin is only worth say $200 melt value with no numismatic value, then it doesn't really make sense to slab it since there will be no increase in value even though it is in the range of where you might consider slabbing.

When it reaches a comfortable potential profit margin for the coin. Less for a known-good, quick-flip coin than one that's more "niche," so actual numbers are hard to define. And I'll cut the margin closer for stuff people would expect to see in a slab, where authentication is important.

I never deliberately buy duplicate coins - I just acquire them when I replace a worn specimen in my collection with a better one, when I bring back loose change from a foreign trip, or when I buy an assortment of coins that includes some I need. I also sometimes pull duplicates from circulation if I get something like a scarce commemorative 50p or £2. Some day I will sort out all my 'swaps' properly and list them on CCF - it would be great to trade them with another collector!

My primary collector interest is Lincoln Wheat cents. I am missing, exactly ONE date/mm (1929 S). 97% of the set is MS (62/3/4/5/6, BN, RB, RD) and the bulk are not worth the grading fees.

But, after searching through thousands of Lincolns, there are a few exceptional specimens that would be close to top pop (NO top pops, just 2nd place!).

I do have duplicates, but most of them, any of you would have a HARD time picking which to choose for your set.

Thank you for the feedback.....it is MUCH appreciated!!