I had to stop and try to think of something that I'd like to be able to find, and I couldn't think of anything, at first. In the past, if something was unavailable, I would try to grow it! That is why I have those makrut/kaffir lime trees - after a time back in the 90s, they couldn't be brought into the country, due to the possibility of bringing citrus diseases into the country, and were suddenly not available! So in 2000 I started them. I don't know if that happened at the same time with curry leaves, too (they are also in the citrus family), but I couldn't find fresh, years later, so I started that one, in 2008 or 9. Demand for these caused them to start growing in this country, and eventually, they were available fresh, though not as good as fresh from the plant, as with anything. Szechwan peppercorns also had this happen for a period of time; fortunately, I had about 3 lbs of those in my freezer, when this started, and still had some, when the importing was allowed, once again!
One thing I would like to see, but probably never will, since it wouldn't ship well fresh, is HojaSanta. Like many herbs, it isn't good dried, and I grew it once, several years ago, and still have a vacuum sealed package for maybe 2 recipes in the freezer, but the last two times the seeds wouldn't germinate. I'll keep trying, since I know it will never be available around here.