Sales quota - too high or just fine?

i m a new 'sales support' - the way they call the position for a granite company, so i spend lots of time answering/directing phones greeting walk in customers etc. for a decent hourly pay. but now they ask me to meet the threshold of 20k usd per month in sales, and 30k/mo by oct. do you think i need to find another job or argue with my supervisor?