I don't know about you, but personally I would much rather someone listen to a dedicated display unit to determine whether he/she likes the sound of something than simply buy something without hearing it first and possibly end up returning it.
In a job interview, there is an unspoken understanding between participants that a position is being offered. I have a sneaking suspicion that the folks at Jaben, by contrast, realize most people listening to the demo units aren't going to end up buying the product. Yet they offer them anyway, and in a sense they benefit because it attracts people to the store.
That's my point, that there is an assumption that someone coming in to audition a product is in the market for that sort of thing, and has not already ruled out buying from that shop prior to even coming in for the audition. I think there's a difference between listening to the $400 xyz iems, e.g., and deciding they are not worth the money, but are good, and then discovering they are much less expensive elsewhere, and therefore worth the money, and buying them. Intention is important here.