I've been looking for a 256 GB micro SD card myself. Here in Central Europe aren't any shops that go below Amazon.de's €80-85 for a Samsung card. I don't really look at anything that is not from Samsung or SanDisk because those are the two most trustworthy manufacturers of SD cards. So yeah, right now ~€80 is the lowest you are going to pay for a 256 GB card. I find it doubtful that higher capacity cards can notably push down the prices of the currently available sizes this year, so if you need a new card now or soon, you'll have to bite the bullet.
Update for my game collection:
Crash Bandicoot N.Sane Trilogy (P)
All those 20e 512gb cards have reviews that state they're pretty much worthless junk, either 16gb cards just hacked to appear to the OS as large capacity or else just chunks of wholely nonfunctional plastic, I'm not sure why Amazon doesn't crack down on them because they get listed at the top if you search by price, but yeah.... anyone who thinks that price is going to end with a giant perfect SD card is joining Kirby in dreamland.
Ta for the advice Rol
Fancy hearing me on an amateur podcast with friends gushing over one of my favourite games? https://youtu.be/1I7JfMMxhf8