Some displays are definitely worth the cost of ISF calibration (not ISL). Professional calibration of CRT front and rear projectors, for instance, are nearly always worth the bucks. Some digital front projectors benefit from calibration also. What do you own? I would assume that it's a digital of some kind - LCD, DLP, SXRD or D-ILA. For these, I would take Ace of Sevens advice and search out a calibration disc and do it yourself. You'll get at least 90% of the way there and maybe more at a quite reasonable cost.