It will take between 7 and 21 days for most of the letters to arrive. That means you will get at least R300 for the 200 copies sent out with your name at number 1. That means you get at least R9000 with your name at number 2. Naturally the more you send out, the bigger the returns you can expect. Try not to delay your decision by more than 3 days, because in this business every day counts.
Time is worth a fortune.