I was intrigued by Dennis Berry's recent thread on the surprisingly low values of some limited production strikes like the Silverton no-dates. So for those of us left brain folks, I went through Bill Cohenour's guide, looking at average recent auction prices for all $10 strikes listed with 500 or fewer production runs. I ran a regression analysis on price vs. quantity issued to see if there is any correlation. There's a pretty good trend line (using a logarithmic scale since prices go way up as quantity goes down), except for three $700 plus outliers at the low production end (Atlantis error, O'Shea's top 50 Leprechaun and O'Shea's Hand Pay -- maybe somebody can explain that). I've attached a link to the graph and data below in case anyone is interested in looking.

There are two spreadsheet tabs -- one with and one without the three outliers. I'm sure some of you more experienced collectors can explain the finer variations in actual prices vs. those predicted by the trend line (% of issue available to collectors, aesthetic design, etc.).

Based on this analysis, the Silverton no-dates should be going for about $225 each, well above the recent auction prices. But this is just a rough first cut at trying to predict prices -- I'm sure there are lots of improvements that can be made. If anyone wants the actual spreadsheet file where you can more readily read the data off the graph by pointing your mouse, please email me. Thanks to Bill who gave me permission to publish some of these numbers from his very useful guide.

--Norm