Hi Swede,
Crossover parts (just caps, inductors and resistors) for a stereo pair cost me about $85US. I didn't go overboard on the parts quality, but I didn't buy cheap stuff either. Of course this doesn't include a huge list of miscellaneous parts: wire, connectors, binding posts, heat shrink, screws, glue, wood, sandpaper, Dacron stuffing, solder, wire ties, tools, paint etc. Since I built them from scratch, I spent just under $500US. However, this includes purchase of a few tools and number of things that weren't completely consumed in the process (solder, connectors, sandpaper, paint, glue etc.). I hope this helps.
Rick