Does the time of year affect the seeds that can be found for sale?
For example I have been trying to track down Stenocactus Sulphureus with no luck. (also checked echinofossulocactus) Or does the commonality/rarity affect the availability? ie. if its really common or been available for a long itme, will be hard to find seeds. (little demand) But the stuff that's not ubber rare will be more readily available, since the general public will be looking for them.
I know a lot of seeds have a pretty good shelf life so this is why I am curious.