Today I spent like 650k on an unlock that I didn't really need and didn't really want, and it reeeeaaally bummed me out. I was zoned out and just kinda saw a big red button on a trainer and clicked it. My brain went into full alarm mode immediately aftarwards, but of course, far too late.
Obviously it's my fault or whatever, but I find it interesting that when I buy stacks of stuff from a player shop it will give me a confirmation when spending around 20-30k. This is a really nice feature. But it's completely absent from training buttons, even when they cost over half a mill.
I don't think it's an unreasonable ask to add something like this, even if only as an optional setting the player can turn on or off.