There has been a softening in the Penny market for some years now...(I exclude the super rareities ..1808 , 1933, 1937 (Ed 8), 1952, 1954) which would probably still attract 'investors' but yer normal pennies have not done that well in recent years ...look at the prices of high grade 1869's 1871's, 1865/3's for example...half what they were at their height and nowhere near where they were even 5 years ago.
Unfortunately and this is a personal view that Pennies are going the same way as stamps (perhaps not quite as bad but in the same vein). Most collectors of Pennies and Stamps are in the older age bracket, when they/we die there is no young blood to replace them ....who under 50 - 60 collect stamps or Pennies.. and where are the young collectors?.
Go to the York Coin and Stamp fair for example and have a look around the Stamp floor and you will see all the evidence you need.
Are any of our children remotely interested in stamps or pennies or coins come to that.
Having said that as much as we poo poo these ridiculous coins coming out every day from that well known marketing company , the Royal Mint, these Jemmima Puddleduck, Thomas the Tank Engine and Andy Pandy coins or whatever, are encouraging people to look and collect again and hopefully some will start collecting more historical coins.....just like tea is a gateway drug to biscuits , Jemmima Puddleduck could be a gateway to Pennies !
My view for what its worth.