I think I am the biggest
Vinylmation fan on the Panel. Over the past two years Vinylmation has become my very favorite Disney souvenir. I have well over 100 of them and can't see my addiction stopping any time soon. Those Nerds Vinyls are some of the cutest aren't they? I've displayed mine front and center in my office.
I've seen no printed information that the Nerds series is limited edition, nor is there anything on the packaging to indicate that this is a limited edition series. However, even the non-limited Vinyls do run out or get discontinued. For example, the first several Park and Urban series are no longer available.
The one indication I have that Nerds are in short supply is that this series was for sale on DisneyStore.com for just a few days and then it was pulled. I have no insider information and know nothing official - really - but my gut tells me that this is a popular series that may have a short sales window. Again, I know nothing official, that's just my guess.
If you're looking a Vinyl that you can't find in the parks or on DisneyStore.com, I suggest that you give eBay a try. There is a very active community of private resellers.
Good luck!