Prepared the Galizian way (pulpo a feira or pulpo a la gallega) they are delicious. And quite simple to prepare, can’t understand why they write intermediare difficulty.
Here are a couple of recipes in German from a very good website (IMO, I have no relation with them). Polpo al forno con patate, the Italian recipe, is very tasty and simple! The Greek way of preparing octopus is also good, first boil it, then BBQ it.
Two problems arise when farming octopodes (can we just say pulpos?): fist, as already mentioned, they are solitary beings that do not like company. They develop cannibalistic tendencies when raised in a crowd (depending on the species too, there are many). Second, they are devilishly clever, they will find a way to escape almost any confinement, as aquarists will testify. Then they die on the floor when they don’t find the way back. That second problem raises the possibility that eating such an intelligent animal may be considered unmoral by some. Still, they do taste delicious!