First of all, anything super expensive is not sustainable. That's almost a tautology - if the majority of the people can't ever afford it, it does nothing for large scale effects of humanity on the environment, nor does it improve most people's lives. Fucking hand-fed berkshire pork is not "sustainable" - it's a fucking indulgence. Small farmers in general are a massive drain on the environment; large scale farming is of course the only way to be sustainable; see aso :
People use "sustainable" a lot to mean "hand made" or "old fashioned" ; like "sustainable wood carved toys instead of mass produced junk from China". Hey, I love hand carved wood children's toys, but "sustainable" ? Hell no. First of all, anything made from wood is not sustainable (a common misuse of the word). But most of all, anything involving a lot of human labor is not sustainable, because it makes it expensive, and it actually makes it massively polluting and gives it a huge carbon cost. A human life has a huge carbon cost (and general huge environmental impact). Anything hand made is massively damaging to the world, and thus again in no way sustainable.
The right way for us to make a sustainable existance is to of course take advantage of the efficiency multipliers of factories and mass production. Anything that produces less product and takes more time and labor is almost inherently less sustainable; there have to be massive other confounding factors for it to make up for it.
Of course if you want "sustainable" toys, the real place to get them is at a thrift store. Reusing is sustainable, cutting off the cycle of constant production of new crap that just depletes resources and increases and toxins and just gets thrown out. But of course the "sustainability" yuppies are just fad-followers so they will buy all new junk and then throw it out when the next fad comes along.