Easy Cactus sells cactus throughout England and the EU, by post. The prices look reasonable. The selection is odd, random even. And they also sell live mealworms. Odd, but true. They sell cactus and carnivorous plants and orchids and live mealworms. Check it out if you live across the pond.
They have a survey of your favorite cactus, and the winner is…. not a cactus at all!
They also keep older latin names, not having updated in what appears to be decades. For instance, here’s a lovely Echinopsis backebergii they offer for sale under the name Lobivia wrightiana.