Working in bare feet seems is risky from an OH & S perspective and certainly would not look good to clients.
I buy Florsheim leather sole shoes every four or so years for under $200 per pair. Get them as seconds to save $$$. The leather sole with some natural moisture ingress provides a static dissipative path to ESD protective floors and also prevents build up of static as you would get with rubber sole runners on carpet. They look professional, feel quite comfortable, protect your toes and you can get them re-soled by a cobbler if need be.
And being a "cost incurred in earning your income" for electronic engineers, they are
TAX DEDUCTIBLE in Australia at least
.
I have worn Florsheims for the last 30 years, avoiding (and refusing) to use those bloody annoying and often useless ESD foot straps and those horrible purpose built ESD conductive shoes. I always tested a PASS on the ESD tester at IBM.