How easy is it to get a real memory stick for PSP?
I've had no luck with the micro SD adapters, as two of them managed to corrupt some of my files even with different micro SDs. I have an old memory stick but want to upgrade from 32 GB to 64 GB and I have heard before that there are a lot of fakes around.
Yea MS fakes were very common. I once had one. And I also don't think there are sticks of that size. The standard maxes out at 32GB. And even that was ~15 years ago, when cards of such size wouldn't be affordable, so I don't think there are many official ones around.
It doesn't mean there can't be working sticks with large capacity, such as repurposed mSD memory chips (or whole cards) with MS memory bus, but I can't imagine that being a large market. So I'd guess that even the working ones would be shitty quality. As in you might encounter the same problems as with the adapters.