1200 INCLUDING tires? A decent set of tires alone will run you 650-800$... You could do it if you got an incredible deal on used wheels.
I've seen a couple sets of OEM 18" 135i wheels for 475-600$, then find decent enough tires within budget. I think that's the only way you can do it.
2007 SLK55 AMG - Black on Gray/Black - AMG 030 Performance Package
2011 135i - Traded
///M-Sport - Dual Clutch - Harman Kardon - Bluetooth - iPod - Shadowline Kidney Grill - 225/255 Star Specs - Hotchkis Front Sway