approx $200 to $250 for a decent calibration hardware, doesnt seem to me to be expensive - but I suppose its all relative. And when you realise that you should recalibrate at the most every 4 weeks, then you'll understand that the price is definitely worthwhile.
I'm wondering what value you place on the time that will take you ?
Worth thinking about I'm sure.
random search for the price for an Eye One (what I use and recommend):
http://www.hot.com.au/product/x-rite...tor-calibrator