1200-1300 for OEM 162 wheels out of a 2006 e90 and RFT tires with 50% tread, I would say you are being optimistic if you are expecting anything more than 600-800 (all wheels + tires), provided the wheels are in great shape.
To put it into perspective, I recently got 19" e46 OEM M3 staggered set of rims (in excellent shape) with Continental ContiSportContact (85% tread left) for 650 bucks.
Sorry to be the bearer of bad news, but did not want you to plan anything spectacular for your new setup, only to find out that you will be way short in cash. Perhaps, you could sell these, and get a decent set of used 19s as an upgrade.
Here is a similar sale: