I have bought some bushes and plants by post from Germany. The prices are very reasonable, but you have to sometimes wait for specific months for specific seedlings (or pay a lot more for them to be packaged with thier pots)
Worth checking out - https://www.gartencenter-shop24.de/
I got 30 lovely bushes for just over 200 chf including post last year and they are really taking off this year.
I've still got some seeds that have proved their fertility by growing. Pm me if you are interested and I'll stick them in the post for you.
7 packets of seeds for three small window boxes was a bit OTT I think