for paint, body, and the e46 assembly Im going to estimate between 2-3 thousand if done well.
You will need a custom hood or a heavily modified e46 hood, custom made trim ring at base of hood and headlights, custom or modified front quarter panels, the headlights themselves, and paint.
<span style='color:gray'><span style='font-family:Courier'>1995 e36 3 Series RIP
1999 e46 3 Series BURN IN HELL
2000 MR-S Roadster= Current</span></span>