It's not about pretending to be from a disadvantaged background. My concern is that an expensive item would be offputting and create a bad impression. I know not to wear Ferragamo/Hermes ties or bold chalk stripe suits.
Right, but I'm saying the only reason to change your normal work accessories is because you don't want to give the impression that you come from a privileged background. However, law firms are not looking to hire only people from deprived backgrounds, but widely, on merit. They are not tossing away CVs that say 'Westminster School' on the basis that those people were given advantage by their parents.
Likewise, if you're a career switcher you might well own a nice wardrobe & handbags from your previous earnings, and it's not something to be embarrassed about: these are things lawyers buy for themselves out of their pay packets and use daily.