Er, what's wrong with carrying $1000 in cash for a special one-off errand?
No-one will know you have it on you if you act normal and don't flash it around, or dart furtively from car to car like you're carrying the Crown Jewels.
Of course I agree it's silly to carry large amounts every day, but for a one-off journey to the apple store, it should be OK.
It's no more dangerous than carrying your new apple macbook or imac back home on public transport, which I see people doing everyday.