Yup, flaps increase lift for take off and provide for the quicker release of suction so to get up on the step quicker(aileron input can help as well).
Yup on the price. The current $139K is for a base model plus the CPI(consumer price index) since 2008. That CPI proviso plus additional development costs I suspect will net out to somewhere between $165-175K base for current deposit holders.