I have assessed five collections in the last ten years. Of these, three were complete individual issues from Oct 1888 through the date of my assessment.

Two of these collections (my personal collection being one of them) I officially appraised for insurance purposes. I first had to convince the insurance companies I knew what I was talking about. (note: an assessment is cursory; and appraisal is extremely detailed)

I have maintained a database of the highest three eBay sales of each individual issue from Oct 1888 through Dec 1917 since December 2008. I provided this spreadsheet along with a copy of my grading standard, loosely based on official comic book grading standards, to the insurance companies. I then explained how I was able to take an issue being appraised and compare it to my data. There is a tricky but very logical formula on how to apply the data for an accurate appraisal for each individual issue.

An appraisal for a complete collection (just the NG Magazines) takes a very long time. I'm not certain I'll be doing it again, at least not any time soon - too much going on in my life.

These "official" grading sites confuse me with their criteria, and I'm not sure I agree with their assessments.

Never-the-less, both collections I officially appraised for insurance purposes came out to be worth well over $100,000.00.

However, no one has been able to sell their collection for anything near these appraisals. In fact, one fella, tried unsuccessfully for five years to sell his entire collection. But then, most of us are hobbyists, not dealers. We don't do it for the money.

Whatever you do - enjoy your time with your National Geographic Magazine collections!