Greetings, Steven!
I am by no means experienced or knowledgeable when it comes to this topic, but here's my two cents, considering what I've seen and heard here in Portugal:
Phitosanitary costs are overwhelming, and the whole process is incredibly bureaucratic, which tends to put most nurseries off of the idea of bringing plants in from overseas. We are a considerably small country, and the orchid market here is incredibly niche. We also have no commercial agreements, as far as I have been told, with the US regarding live plants, so the only way to get those plants would be to bring them into Europe via Germany (or other countries where there is a commercial agreement in place) and then ship them to Portugal. This process is obviously very costly, and ends up being reflected on the final price customers will be paying. I assume it might be the same for other european countries that may not have those agreements as well; for those that do have them, I hope someone from said countries might have better input.
Having said before that the orchid market over here is quite niche, that is also one of the reasons most nurseries end up not investing in breeding - the lack of good matrixes and the overall low demand for those plants (while they're small seedlings, at least) could be reason enough to not put in the time, effort and money. However, that I personally know of, we have Hilmar at Asendorfer breeding and selecting plants, and producing award quality offspring. Still, for the average nursery, this is not an option; the budget to invest is just not there.
So, how exactly do we get our hands on some of our favourites? Well, over here we have a few different options, each with its own drawbacks:
1. Attend orchid shows (and pray to either be able to request what we want from other American breeders, for example, or that they actually have those plants on their pre-order lists)
2. Purchase online from foreign nurseries whenever they have the plants available
3. Get in touch with local orchid societies and/or nurseries and try to get your wishlist plants via bulk imports
Again, all of this is mostly from a Portuguese perspective. Personally, I try to keep my expectations relatively low when it comes to trying to get specific plants, as I know already it will either be a years-worth-of-wait task or half-a-paycheck-for-one-division situation. *cries inside*
I hope this wall of text might be useful in some way, and that someone else can provide more cheerful insights, ahah!
Edit: forgot to add some suppliers. So far, I've gotten most of my orchids from the following sources (the rest were either lucky finds at local nurseries or purchased at orchid shows):
Orchideen Lucke
Lotusland
Großräschener Orchideen
Asendorfer Orchideen
Threaded Mode
