Look to spend around $500-$1500 (USD) on parts. The work isnt too involved if you have all of the correct parts (struts, hubs, rear trailing arms, rear wheel bearing/hub...).
I wouldnt do the swap to put the e46 m3 wheels. I am unsure of their offset and I believe they are 18x8/8.5, you will most likely have clearence problems.
Get a nice set of 4 lug wheels with good rubber and call it a day. No need to go extreme when you wont be using it.