The Collaborative International Dictionary of English v.0.48:
Overvaluation \O"ver*val`u*a"tion\, n. Excessive valuation; overestimate. [1913 Webster]WordNet (r) 3.0 (2006):
overvaluation n 1: an appraisal that is too high [syn: overestimate, overestimation, overvaluation, overappraisal] 2: too high a value or price assigned to something