I don't have much experience buying DL's as there are not that many nurseries in Europe..
That being said, I've ordered from Spain, Belgium, Germany, Slowakia and the Netherlands itself
Buying DL's always seems to be a growing process for me..
I start with going through the sellers webcatalog or -list, writing down éverything I would like to have
Than I go to the NGA and look at the "real photo's"
I find out the height and blooming season and add that to my list of wanna-haves.
Than I send that list to the seller, asking which of those they have enough of to sell
(I noticed that quite often their webcatalog shows DL they don't have (anymore), are sold out or are too small to divide
Out of the ones they mark on my list as being "available" I usually have to make a choice, because there are still waaayy too many
Even than my orders are always over a couple of hunderd to over 1000 euros...
So all in all I have quite a lenghty conversation before we get to the point that I place an order, and they know exáctly what's on my wishlist
Up until now all nurseries have been extreemly generous in sending extra fans (or even entire clumps!) and bonusplants
I've been invited to visit most of them and next year, when things have settled down a bit for me privately, I even may take them up on it
(I would love to see Gerald Hohls' gardens (Boitzer) in peak bloom season!! )