I buy most of my mods used. So many people sell barely used parts because they want to try something different or upgrade to a new car. I also sell my cars stock and part-out the mods separately. It's still expensive but the cost is minimized with this approach. I have been lucky enough to sell some parts for the same price I paid for them.
'13 SSII M3 Coupe - KW Clubsport 3-way (Eibach Front Spring Conversion), Akrapovic Evolution, ESS Tune, StopTech Trophy, IND Euro Front Bumper and Gloss Black Mirror Covers, TMS Studs/Lugs, BMW Performance Carbon Fiber Spoiler/Interior Trim/Center Console, BMW Edition Grills/Gills, BMWPedals Extended DCT Paddles, Mode Carbon GT4 Splitter, Advan TC3 (18x9.5/10.5), BBS E05 (18x10/11), G-Force Rivals (275/35/18, 295/35/18)