Great question. It could be something as simple as the backplate number was made larger or smaller. Doesn't always have to be a drastic change. I'm curious though too... what was different?
I'm a novice here when it comes to large denominations. I own zero. I see no difference, but the internet says, "For the Series of 1934A $500 Federal Reserve Notes, the “mule” designation is specifically tied to the plate number size transition that happened during the change from Series 1934 to 1934A." I THINK it is the front plate number that was supposed to increase in size/font but didn't, someone fact check me. I didn't see a noticable change in the back plate number, but it could be that too. Large = Normal Small = Mule
-Thanks! It is funny you mentioned Polar Currency YT as I just finished reading this thread on Numista & checked his YT channel out. (A good thing to do when you're not buying- check out online resources). It was very interesting & entertaining. The BoC series are fun b/c they have limited runs even now. You can actually acquire some inexpensive tough notes in the polymer series (& then go back to Upgraded Journey & Original Journey). I created my NC Home page centred around World & Canadian Banknotes back in 2019. If you take the link to each series, you'll see how I have identified the best (tough/collectible) prefixes to look out for. Some of the change-overs have less than 1 million released.
I've been building out my collection of star note errors, probably have 5-6 now. One great one with a BEP rejection mark on it too. But I can't find a stuck digit that's not a couple grand. How do you find pricing information on star note errors? I am having a real tough time understanding what I should be paying for certain notes that are error stars. I get sold listings on Great Collections, eBay, Heritage Auctions, etc. But so few come around for sale. Any tips would be awesome! I appreciate you! It's really your fault that I'm collecting these now.
Hey, don't blame me if you blow all your money on these things (lol). I pretty much check the same sources you do. Whether I pay up for a note depends more on how much I can't live without it. I try to buy notes that really catch my eye and are different. By different I mean out of the ordinary. You can always buy missing ink, f to b and b to f offset printings. I like especially strange, folded notes, board breaks, wide gutter notes, etc. Something that is not duplicated on many notes on the sheet. Since there are no price lists for this stuff pay what you feel comfortable with for the particular error offered. Here is a stuck digit (gas pump error) to hold you over. I paid $400 for it a few years back.