500kLs is not enough to reach 2001c. Here's my log when I once did such a run to check commodity prices.
A binary system, with all the good ports on the second star. Distance to the drop in is 500kLS.
So we can be absolutely sure no one in their right mind would consider trading with this station and we're the first person to ever ferry gold there. Let's see what the gold price is there.
At 1c, the trip is still listed at around 9 days.
After 3 minutes, we reach 165c and the clock finally is less than 1 hour. Still accelerating.
5 minutes, clock is down to 15 minutes at a speed at 570c
8 minutes we reach Warp 9 (834c). Clock says 8:30 remaining
10 minutes, we break 1000c. The clock gives us 5:30. Distance is now cut down to 300kLS
Deceleration starts here, from 1030c and 4:30 remaining the speed starts to drop pretty much exactly after 50% of the distance covered.
15 minutes, decelerated down to 575c, 2 minutes remaining for 64kLS
20 minutes we reach 0:07 at 35 LS remaining.
21 minutes finally we arrive at Fleming City. Fuel cost just for the SC 211 credits (I scooped after the jump in)
note: the speed was never affected by any mass. This was 100% acceleration, followed by 100% slow deceleration.