2017 MARKET UPDATE: SUPERGIRL IS NOT SO SUPER
With the interest in Teen Titans, this character is still potentially on the up and up, but sales this year are softening.
I still think it's a good value proposition right now.
2017 MARKET UPDATE:
While the Supergirl TV series got a lukewarm reception, this character isn't going away, thanks to all the DC cinema action coming up. Teen Titans is certain to appear, and will probably feature this blonde heroine.
Low-grade copies are fairly common, and much of the reason for the drop down the Hot Comics list is a sense that investors can afford to wait for better copies. However, the high sale of an 8.0 is a very good sign for the scarce upper end of the market.
In a word... Supergirl. The hottie from Krypton is coming to the big screen, and her first true appearance is on fire in all grades. (See also Superman #123, Supergirl tryout issue, also on the Hot 100 list.)
We are extremely bullish on the value of this book. Not only because the JLA and Teen Titans movie franchises have a chance of running for a decade or longer, but because in general, when compared to their Marvel counterparts, DC Silver Age key issues tend to be tougher to find, and under-valued in the market.
There are plenty of dogs available. Be a little pickier.
When it comes time to sell, you want a fresh, nicely-presenting book which is above average shape, with off-white or white, supple pages. These will sell well.