Man, did you actually SEE those bulged caps yourself or is that just what shop B claimed? I'd want to pop the cover off and look before I trust either of them, cause that's a 30 second check even if you've never opened a PSU before. And what's the 450W brick from, a prebuilt or an old build of your own, cause those OEM units can be straight garbage too. If you're not running some power hungry GPU, that 450W might honestly outlive that 650W with fresh caps anyway.

Tbh the finger trick is smart, but the real issue is people have no idea what lengths look like in real life. Half an inch sounds tiny to them but on straight hair it's basically nothing, while curly hair half an inch can change the whole shape. What works for me is pulling the hair down and showing them on the strand where it'll hit on their collarbone or chin, because numbers mean nothing to most folks. The ones who get really pissed are the ones who wanted a "trim" but actually wanted a full restyle, they just didn't know how to say it.