I just got a job doing 3rd shift grocery stocking, usually they don't allow earbuds but there's no customers so everyone does it anyway.
I'd like to get something ~$30 or less (I don't really care about the sound quality so much as long as it doesn't sound terrible), and battery life lasting at least 8 hours. Wireless because I don't want the wire getting in the way of anything or feeling weird down my shirt.
I got some noise-canceling JBL ones on sale for $90. Pretty good except I have to suck the earwax out of the little speaker grills and then quick-soak it in alcohol sometimes. Maybe they have a cheaper model of them. Battery life and sound quality are pretty good. If Sony has any in your price range I'd go with those.