Susan is trying to decide whether or not to attend college during the next 12-week session. She has the following options: 1. Attend college full-time at a cost of $1200 2. Attend college part-time at cost of $700 and work part-time earning $1,900. 3. Working full-time earning $4,500. What is Susan's incremental profit if She choose option 3 over option 2?