Just to go a bit off topic and challenge this statement... what is "sushi-grade" fish? The limited research I've done is that there isn't a very good definition what "sushi-grade" is and that it's more of a marketing term than a term relating to food safety or regulation.
I'm not 100% sure but I would care to guess that that $5.99 salmon wrapped in plastic at Safeway is safely eatable raw as long as you follow guidelines to kill potential parasites in it (ie. Freeze it for a few days). Might or might not taste that great but it shouldn't give you the runs if you eat it raw.